
Class _ija.23_^ 
Rook nf:> 

Copyright W. 



COPYRIGHT DEPOSIT 



A TEXT-BOOK 

OF 

ELEMENTARY FOUNDRY PRACTICE 



•The 



THE MACMILLAN COMPANY 

NEW YORK • BOSTON • CHICAGO 
ATLANTA • SAN FRANCISCO 

MACMILLAN & CO., Limited 

LONDON • BOMBAY • CALCUTTA 
MELBOURNE 

THE MACMILLAN CO. OF CANADA, Ltd. 

TORONTO 



A TEXT-BOOK 

OF 



Elementary Foundry Practice 



FOR THE USE OF STUDENTS IN COLLEGES 
AND SECONDARY SCHOOLS 



BY 

WILLIAM ALLYN RICHARDS, B.S. in M.E. 

JUNIOR MEMBER A.S.M.E.; MEMBER AM. GAS INST.; AM. CHEMICAL SOCIETY 

INSTRUCTOR IN FORGE AND FOUNDRY PRACTICE IN THE UNIVERSITY 

HIGH SCHOOL AND THE UNIVERSITY OF CHICAGO 

CHICAGO, ILLINOIS 



THE MACMILLAN COMPANY 
1910 

AU rights reserved 






Copyright, 1910, 
By the MACMILLAN COMPANY. 



Set up and electrotyped. Published November, 1910. 



V 

.-3 






Worfaooti 53reeB 

J. 8. Gushing Co. — Hervvick & Smith Co. 

Norwood, Mass., U.S.A. 



©CLA1^7n4in 



PREFACE 

In offering this book to the public, the author would state 
that upon taking up the work of teaching foundry practice to 
boys in secondary schools, he was confronted with the great 
lack of literature on the subject, there being very little of an 
elementary character suitable for use as a text or a reference 
work. 

He has therefore tried to select matter — not too difficult for 
high school pupils and at the same time sufficiently advanced 
for the college student — such as will bring out the largest 
number of principles used in the molder's art; and he has 
endeavored to make everything so plain and practical that even 
without the direction of an instructor the student can put the 
patterns into the sand and achieve good results. 

The patterns chosen may be easily obtained ; moreover, as 
each pattern brings out one or more distinct principles, a 
student who has completed this course ought to be able, with- 
out further instruction, to produce satisfactory results with any 
reasonable pattern. Several supplementary exercises should 
be given to test the grasp of the principles. The author is fully 
aware that a great deal of work found in ordinary foundries 
and involving many principles has been omitted, but this has 
been done only after due consideration of all things involved 
and discussion with able educators. 

It is hoped that the ideas herein presented will be of as much 
value to others engaged in the profession as they have been 
to the author. He freely acknowledges his indebtedness to 
various books and periodicals for ideas received therefrom. 



VI PREFACE 

He is especially indebted to the authors of the following books : 
American Foundry Practice by West, Foundry Practice by Tate 
and Stone, Foundry Work by Stimpson, General Foundry Prac- 
tice by McWilliams and Longair, Pattern Making and Foundry 
Practice by L. H. Hand, and Pattern Making hy S. E. Ritchey. 



CONTENTS 

PAGE 

Introduction xi 

Definition xi 

Foundry Practice — Green-sand Molding — Core Making — Dry-sand 

Molding — Loam Work ......... xi 

CHAPTER I 

Materials 

Sands — Molding Sands (Light, Medium, Heavy) — Free Sands — Core 
Sands — Parting Sands — Facing Sands — Loam — Black Loam — 
Facings — Sea Coal — Graphite — Charcoal — Coke — Talc — Black- 
ing — Fire Clay — Clay Wash — Core Binders . . . . i 

CHAPTER II 

Tools 

Flasks (Ordinary. Snap) — Slip Case — Moldboard — Bottom Board — 
Riddle — Shovel — Rammers — Straightedge — Trowels — Slicks 
— Lifters — Bellows — Sprue Plug — Corner Slicks — Swabs and 
Sponges — Draw Spikes — Draw Plate — Vent Rods — Gater — 
Weight (pouring) — Clamps — Wedges — Pinch Bars — Tool Box 9 

CHAPTER III 
Principles of Molding 

Preparing Sand (Introduction of new sand or facing, Tempering) — 
Ramming (Drag, Cope) — Auxiliary (Crossbars, Gaggers, Soldiers, 
Nails) — Venting — Gating — Risers — Skimming Gates — Shrink- 
age Heads — Patching — Stopping Off 19 

CHAPTER IV 

Molding Exercises without Core 

Ex. I. Rectangular Block — Ex. 2. Cylinder (Solid Pattern). Method 
No. I — Ex. 3. Cylinder (Solid Pattern). Method No. 2 — Ex. 4. 
Cylinder (Split Pattern) — Ex. 5. Application of Principle in Ex. 2 
and Ex. 3 33 



Viii CONTENTS 

CHAPTER V 

Matches 

PAGE 

Definition — Ex. 6. Green-sand Match — Ex. 7. Oil Match — Ex. 8. 

Plaster of Paris Match 41 

CHAPTER VI 
Molding Exercises with Green-sand Cores 

Ex. 9. Simple Green Core — Ex. 10. Grooved Pulley (Two-part Flask) 

— Ex. II. Grooved Pulley (Three-part Flask) — Ex. 12. Column 
Base (Three-part Flask) 44 

CHAPTER VII 
Dry Cores 

Cores — Binders (Flour, Rosin, Linseed Oil, Glue) — Molasses Water 

— Clay Wash — Manufactured Binders — Core Materials other than 
Binders (Wire, Gas Pipe, Cinders, Wax, Charcoal, and Graphite) 

— Composition — Making (Tools, Mixing, Baking, Oven) — Fin- 
ishing ........•••• 49 

CHAPTER VIII 

Molding Exercises with Dry Cores 

Venting Cores — Setting Cores (held by Prints only; held by other 
Means) — Ex. 13. Simple Straight Dry Core — Ex. 14. Setting 
Bolt Hole Core and Core below the Surface (pocket core) — Ex. 15. 
Balanced Core — Ex. 16. Setting Core below the Surface (by Stop- 
ping Off) — Ex. 17. Segment Core — Ex. 18. Hollow Core — Chap- 
lets— Setting Chaplets — Ex. 19. Nailed Core — Ex. 20. Nailing 
Core to Bottom Board — Ex. 21. Hanging Core — Ex. 22. Anchor- 
ing Core with Chaplets — Ex. 23. Anchoring Core with Chaplets 
(Chaplets extending through Cope) 55 

CHAPTER IX 

Miscellaneous Exercises 

Gated Patterns— Ex. 24. Gated Pattern (Plain Moldboard) — Ex. 25. 
Gated Pattern (Match Board) — Irregular Parting — Ex. 26. Mold 
with Irregular Parting — Pattern with Removable Parts — Ex. 27. 
Loose Piece Pattern — Ex. 28. Removable Boss — Draw-rim 
Pulley — Ex. 29. Draw-rim Pulley (with Hollow Core for Arms) 
— Ex. 30. Draw-rim Pulley (with Lifting Ring) — Sweeping or 
Striking Cores — Ex.31. Strike Core 72 



CONTENTS IX 

CHAPTER X 
Open Molding, Sweep and Strike Work 

PAGE 

Ex.32. Open Mold — Sweep Work — Ex.33. Sweep Mold — Strike 

Work — Ex. 34. Strike Work 81 

CHAPTER XI 

Dry-sand Molding 

Description — Ramming — Venting — Finishing — Ex. 35. Dry -sand 

Mold 85 

CHAPTER XII 

Cupola Practice or Melting 

Cupola — Ladle — Tools — Bott Clay — Preparing and Operating the 
Cupola — Pouring — Poured Short — Blowholes — Cold Shuts — 
Scabs — Sand Holes — Swells — Shrinkage Cracks — Warping — 
Fuel 87 

CHAPTER XIII 

Cleaning Castings 

Rattler — Pickling — Sand Blast 95 

CHAPTER XIV 

Chilled and Malleable Castings 

Chilled Castings — Action — Placing Chill — Coating Chills — Gates — 

Depths of Chill — Mixture — Malleable Cast Iron — Process . . 97 

CHAPTER XV 

Brass Molding 

DiiTerence between Brass and Iron Molding — Materials — Flask — 
Clamps — Spill Trough — Drying — Ex. 36. Ornamental Plaque — 
Ex. 37. Brass Molding with Core — Cleaning — Melting — Brass 
Furnace — Operation — Brass and Bronze — To make a Certain 
Composition ........... 100 

Glossary 107 

Appendix — Devoted to Table and Receipts useful in the Foundry . 113 
Index . . 119 



INTRODUCTORY 

Definition. — Foundry practice consists in making sand molds 
and filling them with metal in a liquid form, which hardens into 
what are called castings. 

These castings may be placed into three classes, each having 
distinct physical properties ; such as Strength, Toughness, 
Durability, etc. These are, — 

Gray Iron 

f Brass 
Bronze 
Bell Metal, etc. 
Mild Steel.i 

With special treatment in the mold or after removal therefrom, 
two other forms of iron castings can be obtained ; namely. 
Chilled and Malleable. 

Molding is the making of the molds and the cores used in 
these molds, and is divided into four branches : 

1. Green-sand Work 

2. Core Work 

3. Dry-sand Work 

4. Loam Work ^ 

Green-sand Molding. — This consists in ramming moistened 
molding sand about a pattern in a flask, the impression of the 
pattern being retained in the sand when it is withdrawn. This 
impression is then filled with molten metal, and the casting 
results. Because of its cheapness and quickness, green-sand 
molding is the most common method of making castings. 

1 Not treated in this work. 



xii INTRODUCTORY 

Core Making. — This consists in shaping by means of a core 
box (wooden mold) a mixture of core sand and some binding 
material, and baking the mixture. Cores are used to form 
holes or cavities in castings. 

Dry-sand Molding. — Dry-sand molding consists in making 
an impression of the pattern by packing a core-sand mixture 
about it in a flask, and baking the sand after removing the 
pattern. The baking drives off all of the moisture, leaving 
a hard, clean surface. It is used where rush or bulk of metal 
would be likely to spoil a green-sand mold. 

Loam Work. — This consists in building a mold of bricks on 
which a facing of mortar is placed. This mortar is shaped by 
means of sweeps or patterns, after which the entire mold is 
baked. Loam work is used for very heavy classes of work, 
or where so few pieces are required that it would not pay to 
make ordinary patterns. 



A TEXT-BOOK 

OF 

ELEMENTARY FOUNDRY PRACTICE 



A TEXT-BOOK OF ELEMENTARY 
FOUNDRY PRACTICE 



CHAPTER I 

MATERIALS 

The materials used in the foundry for making molds are 



Sands 

Loam 
Facings 



Miscel- 
laneous 



[ Light 

Molding j Medium 

[ Heavy 

^ , f Sharp or river 

Free sands ' 



[ Beach sand 



f Graphite 
Charcoal 
Sea coal 

I Talc 
Fire clay 



Parting dust 



Core binders 



Sand 



Burnt sand 

Charcoal 

Manufactured preparations 

River 

Beach 
Flour 
Rosin 
Linseed oil 
Glue, etc. 



SANDS 

Sands are the result of the breaking up of rocks by weather 
and the action of water. Rain water lodged in the cracks and 
crevices of rocks, when frozen in cold weather, will cause parts 
of the rock to break off. These parts are carried by the rush of 
rain water down the mountain sides to the rivers, where they are 



2 ELEMENTARY FOUNDRY PRACTICE 

rolled and broken and worn away, to the size we call sand. As 
the current of the river grows less rapid, its carrying power 
becomes less. The heavier grains settle first, so that we find 
gravel or coarse sand, then fine sand, and next a sand and clay 
mixture, with the clay gradually increasing until the sand disap- 
pears and clay only is found. 

Our rocks have very complex compositions. Since our sand 
contains nearly all of the elements of the rock, it is also quite 
complex. 

Molding Sands 

The material which is used in making the molds in the foun- 
dry must be porous enough to allow the escape of the air and 
the steam and gas generated by the heat of the metal poured, and 
yet at the same time compact enough to hold the liquid metal. 
It must be refractory, — that is, able to stand very high tempera- 
ture, — and it must not produce any chemical action with the 
metal at this temperature. It must be readily removed from 
the casting, and leave a clean, smooth surface. 

Sand most nearly fulfills these conditions, as it has no chemi- 
cal action with hot iron ; it allows the gases to pass off readily, 
and at the same time compacts hard enough to retain the molten 
metal and conform to the pattern. 

Selection. — It is very important that a proper sand be se- 
lected for the class of work to be done, for upon this the success 
of the casting largely depends. 

Molding sand used in making molds for cast iron is composed 
chiefly of silica (sand), magnesium, aluminum (clay), lime, and 
some metallic oxides. The proportion in which these substances 
vary, or, occasionally, the presence of some other substances, 
determines the quality and use of the sand. 

There is little to aid the beginner in selecting a molding sand 
or in applying it to its proper use. This either must be left to 
some one experienced in the use of sand or must be determined 
by chemical analysis. 



MATERIALS 3 

To be refractory, a sand must contain a large amount of silica ; 
if, however, it has more than a certain per cent, the sand cracks 
in drying, is not impervious to the liquid metal, and is not com- 
pactable, because of the lack of cohesion. The alumina and 
magnesia are important factors in molding sand, as they render 
it plastic and cohesive. Since magnesia binds the sand very 
thoroughly together, the amount contained in the sand should 
be small, else the porosity will be lost. Alumina has a tend- 
ency to vitrify at the temperature of molten iron, therefore 
the amount must be small. Iron acts in the same way as alu- 
mina and is beneficial as long as the total amount of iron and 
alumina is small. Both metallic oxides and lime are harmful. 
The metallic oxides must not exceed 4 per cent nor the lime 
I per cent. 

Thus it can be seen that a good sand should contain silica 
with a little alumina, and that a small amount of iron and mag- 
nesium does no harm when the whole is so proportioned as to 
fulfill the following requirements : 

1st. A free passage of air, gas, and steam ; 

2d. Withstanding the heat of the metal without fusing ; 

3d. Easy separation from the cold casting, giving a smooth, 
clean surface ; 

4th. Sufficient compactness to resist the pressure of the metal. 

To be serviceable a sand must answer the foregoing require- 
ments. It is obvious, however, that one grade of sand will not 
do for both very light and very heavy work, because the heat is 
so much greater with a large casting than with a small one. 
Also, a large casting need not be so smooth as a small one. 
With the small casting, a sand of fine grain is needed, contain- 
ing a little more alumina than the coarser-grained sand required 
for heavy castings ; and since the heat is less, the sand need not 
be so refractory, and may therefore contain less silica and more 
alumina, as there is less need of venting. The reverse is true 
in the case of heavy castings. 



ELEMENTARY FOUNDRY PRACTICE 



Grades. — This difference in work, or in the size and weight of 
castings, then, gives rise to three general grades of molding 
sands: (i) light, (2) medium, and (3) heavy. The light sand 
is used on small work that has fine details, such as that found 
on stoves. The medium sand is used when the castings range 
in weight from a few pounds to one or two hundred. The 
heavy sand is suitable for large work, such as heavy machinery 
and engines. There is no hard and fast rule determining the 
chemical analysis and the size of the grain in these grades of 
sand ; still, the following will serve to indicate in general the 
amount of sihca and alumina each grade should contain. 



1. Light Molding Sand : 1 

Silica 

Alumina. 

Degree of fineness . 

2. Medium : 

Silica 

Alumina. 

Degree of fineness . 

3. Heavy: 

Silica 

Alumina 

Degree of fineness . 

Sand for brass (very fine) 
Silica 
Alumina . 
Iron 
Degree of fineness . 



82 per cent 
10 per cent 
85 

85 per cent 
8 per cent 
66 



88 per cent 
6 per cent 
46 

78 per cent 
8 per cent 
5 per cent 

95 



The degree of fineness is determined as follows : " An 
average sample of the sand is passed over five different mesh 
sieves, ranging from a 20 mesh up to 100 mesh to the inch. 

1 See the complete analysis in the Appendix. 



MATERIALS 5 

The percentage passing through each sieve is used in the 
determination for fineness. By adding together the amounts 
that passed through each different sieve and dividing this 
by 5, the number of sieves used, one gets the average per cent 
that passed through all the sieves, which number is used to 
designate the grade of sand," or the degree of fineness. For 
example, the amount of a certain sand passing through the 
different sieves is as follows : ^ 

Per Cent 

20 mesh 96.08 

40 mesh 72.60 

60 mesh 26.77 

80 mesh 21.05 

ICO mesh 15.40 

231.90 -^ 5 = 46.38 = degree of fineness. 
This is a coarse or heavy sand. 

Free Sands 

Free sands are sands having little or no clay mixed with 
them. There are two kinds : sharp, or river, and beach sand. 
The sharp or river sand has sharp, angular grains, and the beach 
has round grains. Both are used in core and daubing mixtures 
and for parting sand. The sharp sand is better for the core 
and daubing mixtures, because the angular grains interlock with 
one another, making a strong mixture. 

Core Sands. — Free sand, rock sand, and the debris of abraded 
rock are employed in making cores. Since a core is almost en- 
tirely surrounded by the hot metal, it must be refractory and con- 
tain no alumina, as the alumina would cause the cores to cake and 
be hard to remove from the casting. It should also be free from 
gypsum and salt. 

Parting sand is used on a mold at the joint, or place where 
the parts of the mold are to separate, to prevent them from stick- 
ing to each other. It should have a uniform, fine grain and should 
be free from any substance that draws or retains moisture. Rat- 

"^ A Treatise on Molding Satid. Trade publication of H. S. Vrooman. 



6 ELEMENTARY FOUNDRY PRACTICE 

tier dust (burnt sand shaken from the castings in a rattler), brick 
dust, and pulverized blast-furnace slag make the best partings, 
though charcoal is sometimes used when a very close joint is 
desired for brass work. 

Facing sand consists of the ordinary molding sand with a per 
cent of coal dust or other facing material added to it, and thor- 
oughly mixed and tempered,^ so that the mixture has the proper 
cohesion to retain the form of the pattern against the washing ac- 
tion of the metal when the mold is being filled. For economy 
this sand is riddled next to the pattern and the balance of the 
flask filled with the old sand from the foundry floor. 

Loam is a soil chiefly composed of siliceous sand, clay, and 
carbonate of lime, with some oxide of iron, magnesia, and 
various other salts, and also with decayed animal and vegetable 
matter. It is, next to molding sand, the most important mate- 
rial used in the foundry. Loam will part with its combined 
water at a red heat, and at the temperature of molten iron that 
containing carbonate of lime will fuse and become vitrified. 
Loam containing iron, alumina, and silica is refractory, and 
therefore desirable, while that containing pyrites, lime, and 
alkalies is objectionable. When more than 5 per cent of lime is 
present in the loam, it should be rejected. When flint pebbles 
are present, they should be picked out before the loam is ground 
in a mill. 

Black loam is a cheap loam having strong binding properties 
which make it suitable for mortar for setting the brick work, 
in loam molding, for the first coating of round cores, which must 
be strong, and for sealing cracks. 

I FACINGS 

A facing is a material incorporated with the sand, which is 
riddled next to the pattern or is dusted over the sand after the 
pattern has been removed. 

1 Method of mixing and tempering described in Chapter III. 



MATERIALS 7 

The purposes of a facing are : 

I St. To prevent the sand in the mold from being burned ; 
2d. To make castings peel, — that is, to leave the sand clean ; 
3d. To make the castings smooth and bright ; 
4th. To reduce the expense of cleaning the castings. 

These results are accomplished in two ways : 

1st. By filling the pores between the grains, a smooth surface 

is given to the sand ; 
2d. By burning slowly, owing to the heat of the metal, a thin 
film of gas is maintained between the iron and the 
sand. This film prevents the burning out of the alu- 
mina and the consequent roughness of the casting. 

To accomplish these results the following precautions should 
be observed : 

1st. The facings must be finely ground; 
2d. They must not burn easily; 

3d. They must adhere firmly to the face of the mold, to pre- 
vent them from being washed away by the iron. 

The materials used for facings are the different forms of car- 
bon ; such as sea coal or gas coal, graphite, charcoal, and 
coke. They are used because they will glow and give off gases 
but will not melt. The form in which the raw facing materials 
are obtained makes it necessary that they be ground by passing 
them through a series of crushers, or grinders ; the finest are 
then bolted. 

Sea coal facing is made by grinding screenings of an ordina- 
rily good grade of soft or gas coal, — one that is free from slate 
and low in sulphur. 

Graphite is a soft, greasy, mineral form of carbon taken from 
the earth in large lumps that are much blacker than coal. 
Large amounts are mined in Rhode Island and other parts of 
North America, but the best and purest is imported from 
Ceylon. 



8 ELEMENTARY FOUNDRY PRACTICE 

Charcoal is a vegetable form of carbon made by charring or 
driving off the volatile constituents of wood by means of fire, in 
kilns or in heaps covered with dirt and sod. Either hard or 
soft wood charcoal is used for facings. 

Coke is the carbonaceous matter left after driving off the 
gases from soft coal by heat, in a retort or oven. The coal 
must be very free from earthy materials, so that the amount of 
impurities introduced into the sand with the facing shall be as 
small as possible. 

Talc is a magnesium silicate ore. It makes a good facing 
for some classes of work when very finely ground and shaken 
into the mold from a bag. It also makes a good core wash. 

Blacking is a mixture of a facing, usually charcoal or 
graphite, and a clay wash or molasses water.^ 

MISCELLANEOUS MATERIALS 

Fire clay is almost pure oxide of alumina. It comes from 
the same sources as sand, but is found in a lower stratum, 
having been washed away from the sand by water. It can be 
mixed with water and molded into almost any desired shape, and 
when exposed to the fire, it hardens into a very refractory, brick- 
hke substance. It therefore serves very well as a fining where 
heat is to be resisted, and in daubing mixtures and clay washes. 

Clay wash is fire clay mixed with water to such a consistency 
that it will leave a film of clay on an object when dipped into 
it. It is used as a base for blackings, wetting crossbars of 
flasks, gaggers, and in any place where a strong bond is required. 

Core binders are materials used to stick or bind the grains of 
sand together in making cores, such as flour, rosin, linseed oil, 
etc. These materials are taken up in detail in Chapter VII. 

Manufactured Preparations. — All foundry supply houses have 
specially manufactured or prepared parting sands, core binders, 
facing mixtures, daubing mixtures, and the like. 

1 See Chapter VII. 



CHAPTER II 




Fig. I. 



TOOLS 

In performing the exercises taken up in this work only 
hand tools are used, and only such will here be described. 
They will as nearly as possible be taken up in the order in 
which they are required for 
use in the molder's hands. 

Small work is usually done 
on a bench or bracket project- 
ing from the wall. Large 
work requires that it be done 
on the floor. (The author is 
rather partial to floor work 
and requires the greater portion of the work to be done on the 
floor, whether it is large or small.) 

Flasks. — Flasks consist of two or more frames of exactly the 
same length and breadth, though the heights may vary. The 

frames are used to hold 
the sand while the im- 
pression of the pattern is 
being made. 

The frames are made 
of either wood (Fig. i), 
iron (Fig. 2), or pressed 
steel (Fig. 3). Iron and 
steel flasks are much 
stronger and are used 
where a special class of work is done. Wooden flasks are used 
in jobbing shops, as they are much cheaper. They deterior- 
ate very rapidly, however, and so need much care in handling. 

9 




Fig. 



lO 



ELEMENTARY FOUNDRY PRACTICE 



They should be thoroughly inspected before use. The pressed 
steel flask (Fig. 3) is the most serviceable for school use, being 
lierht and strong and of reasonable cost. 




The parts are held together in the same relative position by 
guide pins and sockets. The pins are in the top part, called 
cope; the sockets are in the bottom and middle parts. The 
bottom part is called the nowel, or drag, and the middle part, 
the cheek. When a flask has but a cope and a drag, it is called 
a two-part flask; when it has three parts, a three-part flask; and 
so on. 




Fig. 4. 



A flask may be ordinary, as shown in Fig i, or a snap flask; 
i.e. one having hinges on one corner and latches on the oppo- 
site corner, as shown in Fig. 4. Snap flasks are used for small 



TOOLS 



II 



work when the pressure of metal on the sides of the mold is 
not great. They range in size from 9" x 12" to i8"x2o". 
The advantage of a snap flask lies in the fact that when a mold 
is made up, the flask can be removed and used again immedi- 
ately. The ordinary flask cannot be removed until after the 
metal is poured. 




Fig. 5. 



Large flasks usually have crossbars in the copes to help hold 
the sand while the copes are being removed. A flask with cross- 
bars is shown in Fig. 5. The number and size of flasks that a 
school should have depend entirely on the quantity and size of 
the work done. Good results can be obtained if there is one 
10" X 12" X 3" two-part steel flask for each student, and aside 
from these for general use three or four two-part snap flasks 
of each of the smaller sizes, and three three-part snap flasks 
of a suitable size for the grooved pulley, Ex. 11. Ordinary 
flasks, like Fig. i, can be made in any school wood shop as a 
regular exercise. 

Slip Case. — A slip case (Fig. 6) is a frame which is 
slipped around the sand, after the snap flask has been re- 





FiG. 6. 



12 



ELEMENTARY FOUNDRY PRACTICE 




Fig. 7. 



moved, to protect the mold until the metal has been poured. 
There should be about three cases for each snap flask. 

Moldboard or follow board (Fig. 7) is a board the size of 

the outside dimensions of the 
flask, and strengthened by stiff 
cleats. The drag and pattern 
are placed upon this board in 
making up a mold. 

Bottom Board. — This is a board 
similar to the moldboard. The mold rests upon this board until 
poured. A school should be supplied with one moldboard and 
two or three bottom boards for each flask. 

Riddle (Fig. 8) is used to sift the sand that comes next to the 
pattern. It should be 16 
to 18 inches in diameter 
with oak rims and galvan- 
ized iron wire cloth, No. 
8-12. 

Shovel. — In the foundry 
the flat-bladed shovel (Fig. 
9) is used for cutting, turn- 
ing, and in general for 
handling the sand. The 
flat blade is best since it is 
often desirable to let the 

sand slide off from the side of the shovel when working on a 
bench. 

Rammers (Fig. 10) are used for tamping or ramming the sand 
in the flasks. There are two kinds, — bench rammers and floor 
rammers. 

The bench rammer is short and made of wood, while the floor 
rammer has cast iron ends on a wooden bar about three and a 
half feet long. In foundries where a great deal of large work 
is done, and where compressed air is to be had, pneumatic ram- 
mers are sometimes used. One end of the rammer is called the 




Fig. 8. 



TOOLS 



13 



peen and is shaped like a dull wedge. It is used for packing 

the sand around the edges of the flask and in the corners of some 

patterns. The other end, called the butt, is 

a short cylinder with a flat face and is used 

for compacting the sand in the body of the 

flask. 

Straightedge (Fig. 11) is a piece of metal 
or wood having a thin edge for leveling the 
sand with the top of the flask. Each student 
should be provided by the school with one 
riddle, shovel, rammer, and straightedge. 

Trowels (Fig. 12) are used for cutting 
the sand down to the parting lines, and for 
shaping the large faces of the mold. 

Three shapes are generally used : (a) The 
square trowel for getting into square corners; 
(d) the round-pointed finishing trowel; (c) 
the sharp-pointed finishing trowel, used for 
both coping out and finishing. The round- 
pointed trowels are the most useful. The 
size of the trowel is determined by the length 
and width of the blade. 

Slicks. — Slicks are used, as their name 
indicates, for slicking over the parts of a 
mold and for patching small breaks. There 
are a great many varieties on the market, used for various 
classes of work. The shapes shown (Fig. 13) are the ones most 
commonly used. Slicks are designated by the shapes of their 




Fig. 





D ^ 




Fig. 10. 



14 



ELEMENTARY FOUNDRY PRACTICE 



blades, and sizes by the widest 
part of the widest blade ; they 
I'l'- II • run from i to i| inches. 

The shapes are {a) taper and square, (d) heart and oval 
spoon, (c) heart and leaf, (d) heart and square. 

Lifters. — A lifter (Fig. 14) has a long, narrow blade on one 
end and a short foot at right angles to the blade on the other. 
They are used for cleaning 
and finishing the deep and 
narrow portions of the mold. ^ ^ ^^ ^ 






Fig. 13. 

There are two styles: (a) bench lifters and {l>) floor lifters. 
The sizes vary from ^" x 10 " to i" x 20" for floor lifters, and 
^^g to I inch for bench lifters. Each student should provide him- 
self with a trowel and either a slick or a hfter. It is well for 
each one to get a little different style. 

Bellows (Fig. 15) are used for blowing the dirt and sand 
from the work. There should be one for every two or three 
students. 

A sprue plug (Fig. 16) is a cylindrical piece of wood, 
tapered. It is used for making the sprue or runner through 
which the metal is poured. The sizes vary with the work and 



TOOLS 



15 



the depth of the cope. The school should be supplied with a 
large assortment, varying from | to i l inches in diameter and of 

various lengths. 

Corner slicks (Fig. 17) are used for 
dressing or squaring the corners. There 
are outside and inside corner slicks, 
ranging in size from i to 3 inches. 
Corner slicks are not much used on small 
work, but it is well for a school to have 
one of each style. 



Se/7cA 




Fig. 15. 



Fig. 14. 



Swabs and sponges are used to moisten 
and pack the sand around the edges 
of the pattern before drawing. Swabs 
(Fig. 18) are usually made by wrapping 
one end of a bunch of hemp fiber, 6 or 

8 inches long, with a few turns of wire. They are generally 

used on floor work. 

By attaching a quill or small round piece of hard wood to a 

sponge to guide the stream of water, a very efficient instrument 

is made. It is well for each student to have a sponge and for 

the school to provide two 

or three swabs. 

Draw spikes (Fig. 19) are 

used for drawing the patterns 

from the sand. There are i^^^. io. 




i6 



ELEMENTARY FOUNDRY PRACTICE 



various styles and sizes : some with sharp points a for driving 
into the pattern ; some with a wood screw point b, and others 



/^/yo e J/r c A 




^^aore Cor/ier 





Come, r 



Fig. 17. 



Conner- 



with a machine screw thread c which screws into a tapped 
hole in a metal pattern, or a metal draw plate attached to a 

wooden pattern. There 
should be one draw spike 
like a for each student, 
three or four like b, and 
one like c for \, |, and \ 
inch holes. 

Draw plate (Fig. 20) is 
a metal plate with a tapped 
hole a in the center and 
one or more other holes 
b without threads. To 
Hft a pattern the draw 
spike is screwed into a. 
The pattern is rapped 
loose by inserting a rod 





ass33tt» 



(T 



c 

Fig. 19. 



TOOLS 



17 



in holes b. By using the holes b for rapping the pattern the 
threads in a are not spoiled. 




Fig. 20. 

Vent rods are sharp-pointed steel rods for making passages 
through the mold for the escape of the gases, steam, and air. 
They vary in size from a small knitting needle to a -^^ or \ inch 
rod. Each student should have a knitting needle, and the 
school should have several vent rods. Drill rods of different 
sizes make excellent vent rods. 




Fic. 11. 



Fig. 22. 



Gater, or Gate Cutter. — A gater (Fig. 21) is a small piece of 
tin about 3" x 4" bent U shape, which is used for making 
the gates through which the metal enters the mold. There 
should be one for each student. 

Weights (Fig. 22) are placed on top of the mold before 
pouring to hold the cope down against the pressure of the 
metal. They should be as large as the 
outside measurements of the flasks and 
from \ to 1 2 inches thick. A school 
should have at least 12 weights. 

Clamps of iron and wedges of wood 
(Fig. 23) are used for the same purpose 
as the weights. Their uses can be clearly 
c 




t 



tVe d 



C/ a mo 

Fig. 23. 



1 8 ELEMENTARY FOUNDRY PRACTICE 

seen from the figure (Fig. 25). Two clamps are needed for each 
ordinary flask and in addition a large number of wedges with 
different angles. 



Fig. 24. 

Pinch bars (Fig. 24) are used to set the clamps on the 
wedges. They are made of steel and are about 12 or 14 inches 
long. Two pinch bars will accommodate a large class. 




Fig. 25. 

Tool box. — A small box (Fig. 26) divided into two or more 
compartments and arranged with a handle for carrying is very 




convenient for floor work. In serving as a handy receptacle 
for the sponge, parting sand, and small tools, it greatly lessens 
the loss of these articles. 



CHAPTER III 

PRINCIPLES OF MOLDING 

To do good work in any trade or occupation it is absolutely- 
necessary to learn the general principles, and in foundry prac- 
tice there is no exception to this rule. 

It is essential in commercial foundry practice to make a mold 
in the least possible time and at the least expense, and it must 
always be borne in mind that these conditions are not reached 
if the castings are unsound, dirty, or not smooth. 

Castings are unsound when they contain imperfections ; such 
as blowholes, porous spots, shrinkage cracks, etc.^ They are 
dirty when they are covered with sand, and are not smooth 
when they have swells, cold shuts, etc.^ In the first case the 
casting is useless and must be made over, while in the two lat- 
ter cases loss of time and expense are incurred in getting them 
into shape. 

The principles that must be followed in making a mold 
that answers the foregoing requirements are applicable to all 
classes of molding, and are : 

1. Preparing the sand by : 

a. The introduction of new sand or a facing; 

b. Tempering. 

2. Ramming : 

a. Drag ; 

b. Cope. 

3. Use of auxiliary holding devices : 

a. Crossbars ; c. Soldiers ; 

b. Gaggers ; d. Nails. 



4. Venting. 



^ See page 93. 
19 



20 ELEMENTARY FOUNDRY PRACTICE 



5- 


Gating. 


6. 


Placing risers. 


7- 


Skimming gates. 


8. 


Shrinkage heads, 


9- 


Patching. 



10. Stopping off. 

I. PREPARING THE SAND 

a. The Introduction of New Sand or a Facing. — The sand must 
be put in condition before a good, strong, clean casting can be 
made. 

In light work, when the sand is not burned too much, these 
requirements can be met by the addition of a little new sand, 
every day or so, according to the amount of work done. In 
heavy work the amount of sand next to the pattern is small in 
comparison with that necessary to fill the flasks. Therefore the 
sand is kept in condition by strengthening the heap occasionally 
with a little new sand, while that which is riddled next to the 
pattern should be treated with a facing mixture varying with the 
thickness and weight of the casting. 

Too much new sand causes the mold to crack — this is due to 
lack of venting — and not enough, causes cutting of the mold or 
scabbing of the casting. Too much facing mixture makes ex- 
cessive gas, causes blowholes in the casting, and makes the 
sand brittle and hard to work ; while too little facing mixture 
results in dirty castings. 

The correct proportions are: One part of facing mixed with 
six, eight, or twelve parts of sand. The amount depends upon 
the weight and size of the casting to be poured as well as the 
time of pouring and the intended fluidity of the metal. This 
may be more definitely stated thus: Castings \ inch or less in 
thickness need no facing, as well-riddled heap sand gives better 
results. For castings \ inch to i inch in thickness, use one 
part facing to fourteen parts of sand; for those from i inch 
to 2 inches, use one part facing to from eight to ten parts 



PRINCIPLES OF MOLDING 21 

sand, and when thicker than 2 inches, one part facing to from 
six to eight parts sand. When the sand is new, less sand should 
be used. 

When a facing is to be added to the sand, the two must be 
thoroughly and evenly mixed by handling over and over; other- 
wise a bad casting will be obtained. 

The materials should be as dry as possible. The sand should 
be spread out in a thin layer, and the new sand or facing material 
distributed over it as evenly as possible; it should then be cut 
over with a shovel a few times, and well riddled with a No. 6 or 
No. 8 riddle. It is then tramped down, wet, and tempered in the 
same manner as heap sand. (See Tcuipcrijig in the follow- 
ing article.) After this it should be riddled through a No. 4 riddle 
two or three times. It is then in condition to be used. 

b. Tempering. — The sand is tempered for use by wetting it 
down. Water is thrown on to it from a pail ^ or with a hose or 
sprinkling can, and the sand is then turned over from top to 
bottom with a spreading motion so as to intermix the wet por- 
tions with the dry. This must be repeated until the sand is 
evenly moistened and all lumps broken. It must not be wet 
enough to feel soggy when squeezed in the hand. When an 
egg-shaped ball can be held between the fingers and thumb of 
each hand and broken, and the edges remain firm and sharp, the 
sand is in good condition. If the sand is too wet, the hot metal 
will generate steam and cause blow holes in the castings; if it 
is too dry, the metal is likely to crumble. 

2. RAMMING 

The sand is rammed to make it stick in the flask and to give 
the mold strength to withstand the flow of the metal. The hard- 
ness to which the sand in a flask should be rammed depends upon 
several things; such as the size of the mold, the size and the 

1 The pail should be given a turning motion so as to cause the water to spread 
out into a sheet. 



22 ELEMENTARY FOUNDRY PRACTICE 

condition of the sand, and the weight of the casting. This can 
be learned only by experience. 

When the sand is rammed too hard, blow holes are caused, 
since the natural vents are closed up. When not rammed hard 
enough, the sand will either sink under the weight of the metal, 
or be forced or bulged out, owing to the pressure, and a swelled 
casting is the result. Also, when loosely rammed, the sand may 
be washed from the face of the mold, and the casting will be 
marred by scabs and sand holes. 

The bottom of the mold must stand the weight of the metal; 
therefore it must be rammed harder than the cope. The joint — 
that is, the place where the parts of the mold separate — should 
be rammed hard, for it is exposed to much handling. The mold 
should be left as soft as possible, but it must be hard enough to 
hold the casting in proper shape. Beyond this the risk of losing 
the casting increases with the hardness of the ramming. 

The following general directions should be observed in ram- 
ming all molds : 

a. Ramming Drag. — When the depth of the drag is less than 
5 inches, it should be filled heaping full of sand. If it is 
greater, it should be filled to a depth of 5 or 6 inches. The 
sand is then rammed around the edge of the flask with the peen 
of the rammer,^ next about the pattern, and finally the sand be- 
tween the two, or the remainder of the flask. On small work 
the sand over the pattern should not be rammed with the 
peen, nor should the rammer strike nearer to the pattern than 
I inch, or a hard spot will be formed in the sand. When but 
little more sand is needed, the drag should be filled heaping 
full and rammed with either the peen or butt end of the rammer. 
If the mold is deep, another layer of sand 5 or 6 inches deep is 
added and rammed with either end of the rammer. When the 
mold is large, time can be saved by tramping the sand before 
butting. 

1 When a floor rammer is used, the rod must be grasped firmly with both hands. 
Never put one hand on top of the rammer. 



PRINCIPLES OF MOLDING 23 

b. Ramming Cope when there are no Crossbars. — If the depth 
of the cope is 5 inches or less, it is filled heaping full of sand 
and rammed with the peen, first around the edge and then over 
the rest of the cope. If more sand is needed, it can be added, 
and the cope rammed all over with the butt of the rammer. 
If the pattern should extend into the cope, care must be observed 
not to strike the pattern. 

When the cope is deep, it is filled to a depth of 5 or 6 
inches and rammed with the peen, first around the edge and then 
over the rest of the cope. More sand is then added and the 
ramming repeated until the cope is filled. The butt of the ram- 
mer must not be used until the cope is entirely filled or the suc- 
cessive layers will not stick. It should be used, however, for 
the final top ramming. 

When the Cope has Crossbars. — When the cope has crossbars, 
each compartment is rammed as a separate cope. Care must be 
taken to have all the sand rammed with equal hardness. 

3. AUXILIARY HOLDING DEVICES 

To avoid excessive ramming in the cope various devices are 
used to hold the sand, such as {a) crossbars, {b) gaggers, 
(r) soldiers, and (//) nails. 

a. Crossbars and Gaggers. — Crossbars, shown in Fig. 5 and 
at a in Fig. 27, are placed in the cope to prevent hard ramming, 
by dividing the sand into small bodies. 

b. Gaggers {b, Fig. 27), L-shaped pieces of iron, usually -^^ or 
\ inch square section, are used in connection with crossbars to 
anchor the sand. They are held against the crossbar by the 
pressure of the sand on the long leg, while the short legs hold 
the sand above it. Therefore to have the gaggers most effec- 
tive the long leg must be placed squarely against the crossbar, 
plumb, so that the short leg comes near the place where the 
sand in the cope and drag part. The long leg should extend at 
least two thirds of the way to the top of the crossbar, the higher the 



24 



ELEMENTARY FOUNDRY PRACTICE 



better, as long as it does not project above the top of the cleat. 
If it projects, the gaggers may be struck and the mold spoiled. 
Gaggers are shown properly set in Fig. 27, and improperly in 
Fig. 28. 




-^^ 



Fig. 27. 



c. Soldiers. — Strips of wood {a. Fig. 29) placed in the sand 
to anchor the body together are called soldiers. They vary in 
size, shape, and length to suit the conditions of use. Soldiers 
have great holding power and are, therefore, much used to hold 




^^^ 



^^^ 



Fig. 28. 



hanging bodies of sand, often eliminating the necessity for spe- 
cial bars when placed beside the regular crossbars. When sol- 
diers are used, they must be wet with clay wash and then pressed 
into place in the sand, and the sand rammed. A thin layer of 



PRINCIPLES OF MOLDING 



25 



sand must always cover the soldiers, to prevent their burning as 
well as to separate them from the parting surface. 




f^^J 



^^ 



Fig. 2g. 



d. Nails. — Nails are often used to hold green cores, points, 
and corners of molds. They are pressed into the sand after 
it is rammed, in such a manner that the head will hold the 
sand. The nail should, however, be completely covered with 
sand. 

4. VENTING 

Venting a mold, or the making of passages for the escape of 
gas and air in the sand and the steam generated by the liquid 
iron coming in contact with the damp sand, is one of the 
most important details in molding. If the gas, air, and steam 
are not given an opportunity to escape, the casting is sure to be 
spoiled. Either the mold will explode and the iron be forced 
out of the runner, or some parts will not be filled with iron, on 
account of the pocketing of the gas, which prevents the iron 
from flowing into these parts. If it were not for the necessity 
of providing for the escape of the gas, air, and steam, molds 
could be rammed much harder, and a much better and smoother 
casting would result. 

In venting a mold the following facts must be heeded: 
New sand needs a great deal of venting, as it contains much 
gas ; sand mixed with sea coal or coke dust needs still more. 



26 



ELEMENTARY FOUNDRY PRACTICE 



The bottom requires much venting because it is completely 
covered with iron. 

Copes are vented more to allow the escape of air in the 
mold than for the escape of gas and steam. 

Copes having projections, flanges, or pockets in them re- 
quire such places to 






^ 



I" /■■■•-'■■"'•v.- -'•.^■..■■;''-->-;r----xv .»•.•.•.--'-'.:-■••'- ■;-•>'. 
•■■''■ .' .I'., I* :.-'>:"';,r-/.-..-::5.-^e/r 6/ .■:'.-: f-:--'--V-:v. •': --<.»;'., 
',",.'/..' :^,!■■^■ ;-^^.;<:■;;^■';:,.:^.C^-^l^■^ :.'..:-:.:-:-X ' ';•- ■.'^. ■-.■-,•.-•. 



t\ 



v,:i^V;: 



;;^^ii 






ii 



be vented. 

Molds to be poured 
very fast must be 
amply vented, so 
that the air, gas, 
and steam may pass 
off rapidly. 

Less venting is re- 
quired when a mold 
is poured with hot 
iron than with 
chilled, since the hot 
metal has life enough 
to force the air 
through the sand 
pores. In the case 
of cold iron, the com- 
pressed air, unless 
it finds ready escape, 
will hold back the iron 
so long that it will 
cool. This leaves 
the casting with 
smooth, flat hollows 
in the cope part. 
In venting copes for light or heavy castings very little dif- 
ference need be made as regard closeness of vents, but for 
light work the vents should extend to the surface of the mold, 
while heavy work should be vented to within 2 or 3 inches 






■;A'J 


•vLl^ 


¥ 


.t. - - 


'^' > 




'.'''• "■ 




\^ 


•-.^ 




-^-- 


(■'= 


-..■ - — 


•1*' 








■'/\ 


^?:-" 


t-fr 


.•*• •' 


■.IV; 


•:|.-.- 


;-''; 


,'-v. 


'1-.'- 



■• ii^i- 



;'-r^)/::-'-:.-i: 



•j;:l~.'K-- 



g"..^.-^: 



• ■'■'■i'''-' 






iiiiiiiiiili 



■^^- 



Fig. 30. 



PRINCIPLES OF MOLDING 



27 



of the surface. Molds for heavy castings require venting 
along the sides, as shown in Fig. 30. The vents are shown 
at a. These connect with the channel b, through which the 
gases are carried to the risers at c-c, where they escape. 

The bottom surface of the drag should be crisscrossed with 
a slick to form passages for the escape of the gases between the 
sand and the bottom board. 

In pouring, the gases passing from the mold should be 
lighted as soon as possible because they are very poisonous. 

5. Gating 

Gates are openings formed in the sand through which the 
metal enters the mold. These openings are composed of three 
parts : (i) basin, (2) runner or sprue, and (3) gate. The basin, 
shown at b, Fig. 31, is a depression shaped by hand on top of 
the cope and connected with the runner. The runner or sprue 
{c, Fig. 31) is an opening 
through the cope, found by 
setting a plug of wood, called 
a sprue plug. The gate d. 
Fig. 31, is the opening that 
connects the runner with the 
mold. It is cut with a gate 
cutter or gater (Fig. 21). 

The object of gating is to 
fill the mold quickly with perfectly clean metal and with as 
little disturbance as possible. 

There is nothing in the art of molding that requires more 
care than the making of basins, runners, and gates. Bad gates 
are often responsible for bad castings. The mold may be 
slighted and a casting comes out all right, but ignorance or 
carelessness in gating will almost always cause trouble. 
The following general rules should be observed in placing 
gates : 

I. Section should be wide and shallow. 







'■^■f^'--- -'-■ ■'■» "' ■■■■■-■■ t li -a Ji J 







t»V\ M 



K5tfe>j ' 



Fig. 



28 



ELEMENTARY FOUNDRY PRACTICE 



2. They should be located where the natural flow of the 
metal will fill the mold quickly. 

3. They should be placed where the sprues can be easily 
broken or ground off. 

4. There should be gates enough to allow the metal to fill all 
parts of the mold. 

5. The runner or sprue should not be over | inch in diam- 
eter on ordinary sized work. 

6. The point d, Fig. 31, should have the smallest sectional 
area of any part of the gate in order that the basin and runner 
may be quickly flooded and kept full of metal. This will 
give a strong head on the mold. 

7. The end e should be the deepest. There should be a 
low dam at the entrance to the runner, as shown at/. 

Figure 42 shows a properly made gate for a rectangular cast- 
ing, and the riser is made in a similar manner. Their location 
is shown in Fig. 41. If the casting is long, the sprue should be 
placed at the middle and gates made to several places along 
its length as shown at a-a-a in Fig. 32. In this case it is 
well to place two risers on the opposite side at the ends, as 
shown at b-b, or one riser at the middle connected by gates 
with the ends. 

Figure 46 shows the placing of gates for a cylindrical casting. 
If the cylindrical casting is long, gates can be branched as 
shown in Fig. 32. The gates should be cut so the metal will 
enter the mold at the center line. 

It is often necessary in order to fill a mold to have the metal 
enter with greater 
force than can be 
obtained due to the 
head in the cope. 
In such cases a pour- 
ing head or outside 
basin is used. A 
pouring head consists of a small frame in which sand is packed 




Fig. 32. 



PRINCIPLES OF MOLDING 



29 



and a basin and runner formed as shown at a, Fig. 33. The 

runner b of the pouring head 
is placed directly over the 
runner c in the cope, thus 
giving a much higher head. 
For a sphere the gate and 
riser should be located as 
shown in Fig. 33. The pour- 
ing head a is needed only 
when the height 
of the sand in the 
cope above the 
pattern is small. 




Fig. :iz. 




Figure 48 shows the position in which the sprue 
should be placed in making a handwheel, and it 
should be placed in a similar way on all types of 
wheels, pulleys, or shieves. If the hub is to be 
cored, the sprue will be set to one side of the core. 
Figure 5 1 shows the placing of a gate on a short 
cylindrical casting, cast on end. 

It is sometimes desirable to pour a casting from 
the bottom. Figure 61 shows the way of doing ^^' ^'^' 

this in a three-part flask. In a two-part flask a horn sprue is 
used. A horn sprue (Fig. 34) is a sprue similar in shape to a 
cow's horn, circular in section, and tapered from one end to the 

other so that it can be easily 
drawn from the sand. 

Figure 35 shows the use ; 
a is the horn sprue in position. 
The large end is flush with 
the parting line and an ordi- 
nary sprue b is placed in the 
cope directly above it. The 
shape of the sprue makes it 
Fig. 35. easily removable. 




so 



ELEMENTARY FOUNDRY PRACTICE 



Figure 119 shows the way of making gates for thin brass 
work. 

6. Risers 

Risers, shown at a, Fig. 31, serve a threefold purpose: 
(i) as a vent; (2) as a skimming gate ; (3) to supply the metal 
as the piece cools. 

Risers are made in the same manner as the runner for a gate, 
but with a diameter about one third larger. In a small casting 
the riser should be located where it will best catch and carry off 
the dirt. In castings where it acts as a feeder, it should be 
connected as nearly as possible to the heaviest part of the cast- 
ing, and must be large enough to prevent the freezing of the 
metal in it before the casting: has set. 



7. Skimming Gates 

Skimming gates, shown in Fig. 36, are for removing the dirt 
and impurities which all melted iron contains and which rise 
^, . to the surface of the 



* ; '■•7 






; ^y^}^:^UA<^q-y:i:Z}'-::^:}^M Mofc/\ 



y'f.'^'JA^' 



'■• .1 'I-' •■ liTy^ . . .J^ *-"' . . — TT"' .. .« , 



Fig. 36. 



metal. To insure a 
clean, solid casting 
it is of importance to 
have the runners and 
gates made in such a 
way as to collect the 
dirt before the metal 
enters the mold. 
The riser should be 
large and the con- 
necting gate (Fig. 
36) curved, to give 
the metal a whirling 
motion which tends 
to send the dirt to 
the top. 



PRINCIPLES OF MOLDING 



31 




Fig. 37. 



8. Shrinkage Heads 

Shrinkage head, or sinking head, is a prolongation on a cast- 
ing to supply metal to replace shrinkage. 

The metal that comes in contact with the face of the mold 
solidifies rapidly and the liquid metal is drawn to 
these faces, leaving the interior hollow or very spongy. 
The lower part of the casting, having the pressure of 
the metal above it to draw from, resists this shrinkage, 
and unless the top is supplied in some manner with 
new metal it will become cupped, as shown in Fig. 37. 
In small castings the gate runners and risers supply the needed 
metal and pressure, but in large castings it is necessary to have 

a large riser (Fig. 38), called 
a shrinkage head, connecting 
•;■•;•;-' directly with the casting. In 
'■■■'■ order that the shrinkage head 
'■'\' may be easily removed after 
■}':, the casting is cooled, the section 
":';' is greatly reduced where it is 
■'y;:_ attached to the casting. To 
yj]. prevent the metal from freezing 
f/v' in this reduced section, a feed- 
^V-': ing rod b is used to churn the 
metal slowly up and down. 






a 




Ca^t/njg 



Fig. 3S. 



9. Patching 

Many molds can be saved by patching; thus allowing the use 
of old or improperly made patterns. It is in patching that a 
molder shows his skill. Sometimes a good molder will be able 
to repair a mold that seems to be ruined, but one must have 
practice and experience to do good patching. 

The beginner should carefully observe the following rules : 
Dry or properly tempered sand cannot be patched without wet- 
ting, but care must be taken, however, not to get the sand too wet. 



32 ELEMENTARY FOUNDRY PRACTICE 

Patching should be done with the fingers wherever possible, 
as the castings are less likely to be scabbed. 

Sand put on with the fingers can be added to ; that which 
is slicked on cannot. Little slicking should be done as it will 
make hard spots on the castings. 

Nails should be used to hold the sand in making large patches 
and should be completely covered. 

Patching in a deep mold is done by lowering small balls of 
sand on a tool to the proper place, and pressing them on by 
light slicking. 

A corner is patched by holding a tool with a straight face on 
one side and pressing the sand into the other. 

All loose sand must be removed, for it will wash into the mold 
and cause a poor casting. 

The beginner may not at first be able to save a mold that has 
been injured, but will, by practice and the exercise of a little 
patience, soon get results, and learn that a mold should not be 
discarded without first making an attempt to patch it. 

10. Stopping off 

Stopping off is filling with sand the impression left by some 
part of the pattern not desired in the casting ; e.g. castings 
having the same section but different lengths can be made from 
the same pattern, if the pattern be made the length of the long- 
est casting and the molds " stopped off " at the proper lengths 
for the others. 

In "stopping off" a mold to make a shorter casting, a "stop- 
ping-off piece " the shape of the section is held at the proper 
place. The sand in the part to be " stopped off " is roughened 
so the new sand will take firm hold. Sand is then packed into 
the space not required, and after this the " stopping-off piece " 
is removed. 



CHAPTER IV 

MOLDING EXERCISES WITHOUT CORES 

Each of the first four exercises in this chapter brings out one 
of the four fundamental principles used in all green and dry- 
sand molding. Hereafter not a mold will be made that does not 
use one or more of these principles. It is important, therefore, 
to get these steps well fixed in mind. 

Exercise i . Recta7igular Block. 

Pattern ) ^ , i , , 

^ . \ Rectangular block. 
Castmg ) 

To make the mold : Place the pattern about centrally on the 

moldboard, with the widest face ^ on the board. Place the drag, 

with sockets down, over the pattern as shown in Fig. 39. 

Riddle enough well-tempered molding sand^ into the drag to 



I "^-^ -"^y ^Tz:^ 



^^^ 



Fig. 39- 




1 Draft. — In order that a pattern may be drawn from the sand, it is made with a 
taper from the parting line (the place where the mold separates) to the opposite 
edge. The larger dimensions are at the parting line. Thus on the pattern used in 
Ex. I, the dimensions of the face that is placed on the moldboard (the part that 
is at the parting line of the mold) are about ^ inch greater than on the opposite 
face. The ends of the cylindrical pattern taper from the center (the parting line) to 
the circumference ; i.e. the length at the center is greater than at the circumference 
or at any place between. 

All patterns are either modifications or combinations of rectangles and cylinders, 
and must be made with the proper taper or draft. A study of the draft on a pattern 
will indicate along what line or lines of the pattern the mold should separate, and 
therefore how the pattern should be placed into the sand. 

2 See Tempering Sand, page 21. 

o . 33 



34 



ELEMENTARY FOUNDRY PRACTICE 



cover the pattern. With the fingers pack the sand about the 
pattern. Fill the drag heaping full of sand (unriddled), taking 
care that no foreign matters goes in. (Ram sand as directed 
under Ramuiing, page 22.) With the straightedge strike off 

the excess sand until level with 



the face of the drag. Throw 
a handful of sand free from 
lumps on top of the sand (in the 
drag). Place the bottom board 
over this, as in Fig. 40, and 






=-.>A..i:.i.-.:.\:y,^^-.-, 



^g;>i 



L 



Fig. 40. 



slide it back and forth a few times to seat it well. Remove bottom 
board. Punch several holes to the pattern with a vent wire; 
then replace the board. Grasp the bottom and moldboards at 
the ends, holding the drag tightly between them, turn over and 
rest the drag on the bottom board. Remove the moldboard. 
Blow off any loose sand with the bellows. Smooth the face of 



/Runner, 



H/set 



V 







'.f.*."--.":;'c-!'',';>:~>r/ •' 




the mold about the pattern with slick or trowel. Make parting 
by sifting through the fingers enough parting sand to cover the 
joint (the place where the mold parts). Blow off excess parting 
sand with the bellows, being very careful that none remains 
on the pattern or edges of the flask. Place the cope in position 
and insert plugs for sprue and riser as shown in Fig. 41, about 
1 1 inches from the pattern. Riddle enough sand to cover the 



MOLDING EXERCISES WITHOUT CORES 



35 






•^<'.. 






'*<<-:V. 



' «-*■» t% •^■^ /• ' V v»i^,».' Vi- : \i 




h><N V >yr^.AA>^ 



face of the pattern, and fill 

and ram the cope as described 

under Ramming, page 23. 

With the vent wire punch 

several ventholes down to the 

pattern. Remove the sprue 

and riser plugs, first giving 

them a few turns to loosen 

them. Make pouring basin 

as shown at b, in Figs. 31 

and 42. 

Carefully Hft off the cope 

by raising it straight up until 

the pins are free. Stand the 

cope on edge or rest it against the moldboard, as in Fig. 43.^ 

Wet very slightly around the edges of the pattern with the 

sponge or swab. Drive the draw 
spike into the pattern at the center 
(Fig. 44). Rap the draw spike 
slightly on all sides. This will 
loosen the pattern and pack the 
sand at the edges of the mold. 
Then lift and remove the pattern. 
Cut the gate as shown at d in Fig. 
31, and connect the mold with the 
riser in a similar manner. Blow 



Fig. 42. 




Fig. 43. 



through sprue hole to remove 
any loose sand. Place the cope 
into position and cover with 
weight, or clamp it, as shown in 

Fig. 25. 

1 The cope in small work can be laid 
flat on the moldboard, but the board must 
be placed on the cope and both the board 
and the cope lifted and turned at the 

same time. 




Fig. 44. 



36 ELEMENTARY FOUNDRY PRACTICE 

This first exercise should be poured in iron, as no other sub- 
stance shows so well whether the mold has been rammed, vented, 
and gated properly.^ 

Exercise 2. Pattern Cylinder {Solid Pattern). Method No. i. 

To make the mold : Place the pattern centrally on the mold- 
board so that the long axis of the pattern is parallel with the 
long edge of the board, or in a way similar to that in Fig. 39, 
and place the drag in position. Riddle enough well-tempered 
molding sand into the drag to cover the pattern. With the 
fingers pack the sand about the pattern. Fill the drag heaping 
full of sand by shoveling from the heap, picking out any foreign 
matter that may be in the sand. (Ram up the drag as 
directed under Ramming, page 22.) Strike off the excess 
sand with the straightedge. Throw a handful of sand free 
from lumps on top of the sand. Place the bottom board over 
this, as in Fig. 40, and slide it back and forth a few times to 
seat it. Remove the bottom board and vent the drag by punch- 
ing several holes to the pattern with a vent wire ; then replace 

1 Soft Metal. — When a school is so situated that a cupola for melting iron cannot 
be installed or the expense of one is too great, soft metal (metal melting at a low- 
temperature) can be used with very satisfactory results. Lead melts very easily and 
runs and fills the mold very nicely. It has one fault for school work or any place 
where it is to be used over and over again, in that a casting made of lead alone can- 
not be broken easily, when it is too large to be placed in the ladle or crucible. 
But by mixing a small amount of block tin, bismuth, and antimony, a composition 
that is brittle can be made, which answers the purpose splendidly. In making a 
mixture, the following proportions will answer in most cases ; 94 per cent lead, 
2 per cent tin, 2 per cent antimony, and 2 per cent bismuth. If this mixture produces 
a casting too tough, add a little more antimony and bismuth. 

An alloy of 95 per cent aluminum and 5 per cent zinc (alzine) melts at but little 
higher temperature than the above alloy and is suitable for use when small articles 
are to be saved. 

These alloys can all be melted in the brass furnaces described under Brass Molding, 
page 103, or in a forge fire. A good substitute for a furnace for melting these soft 
metals is an old cast-iron depot cannon stove used for burning soft coal. 

Plaster of Paris is very good for filling molds, and acts very much like cast iron. 
A mixture of 3 to 3| pounds of the plaster to a quart of water makes the best 
castings. It should be stirred until it sticks to the hand when dipped into it like 
cream. Should the plaster set too rapidly, the setting can be retarded by adding a 
small amount of salt or vinegar. 



MOLDING EXERCISES WITHOUT CORES 



37 



the board. Grasp the bottom and mold boards at the ends, 
holding the drag tightly between them ; turn over and rest the 
drag on the bottom board. Remove the moldboard. With the 
trowel and slick pare the sand away to the center line of the 
pattern all around, as shown 



in Fig. 45. Make as long a 

slope as the size of the flask 

will permit. Great care must 

be taken to cut to the exact 

center of the pattern. Put on 

parting sand by sifting through 

the fingers. (Have the joint 

well covered, but avoid having 

an accumulation of sand along 

the edge of the pattern by 

blowing off the excess sand 

with the bellows.) Place the 

cope in position, taking care 

. Fig. 45- 

that no sand remains on the 

edges of the drag, and place plugs for the sprue and riser about 

i|- inches from the pattern, as shown in Fig. 46. Note that the 






Fig. 46. 



riser is gated from the highest part of the mold. Riddle sand 
till the face of the pattern is covered, and fill and ram the cope 
as described under Ramming, page 23. Make several ventholes 



38 



ELEMENTARY FOUNDRY PRACTICE 



down to the pattern. Remove the sprue and riser plugs, first 
giving them a few turns to loosen them. Make pouring basin, 
as shown at b in Fig. 31. Carefully lift off the cope by raising 
it straight up until the pins are free. Stand the cope on edge 
or rest against the moldboard, as in Fig. 43. Wet very slightly 
around the edges of the pattern with the sponge or swab. Rap 
the draw spike slightly on all sides, to loosen the pattern. Lift 
and remove the pattern. Cut the gate as shown at d, Fig. 31, 
and connect the mold with the riser in a similar manner. 
Blow through the sprue hole to remove any loose sand. Place 
the "cope in position and cover it with weight, or clamp it, as 
shown in Fig. 25. 

Exercise 3. Cylinder {^Solid Pattcrii). Method No. 2. 

Pattern and casting same as in previous exercise. 

To make the mold : Place the pattern on the moldboard 
exactly as in Ex. 2. Place the drag in position and raise it with 
wedges under the four corners of the drag, so that the bot- 
tom edges are exactly on a level with the parting line of the 
pattern, as shown in Fig. 47. To tell when the drag is at the 




proper height, sight across the bottom edge of the drag, and see 

that the two edges and the parting line of the pattern are in 

line. Another method is to stretch a string from edge to edge 

of drag and then adjust wedges until the string coincides with 

the parting Hne of the pattern. Riddle on enough molding sand 

to cover the pattern.^ Pack the sand around the pattern with 

the hand as in the preceding exercises. Fill the drag heaping 

full of sand from the heap, and ram as directed under Ramming^ 

^ Some of the sand will pass out of the opening between the flask and the board, 
but this space will soon fill up. 



MOLDING EXERCISES WITHOUT CORES 39 

page 22. Strike off the excess sand, throw a handful of sand 
on the drag, and seat the bottom board, as in previous exercises, 
by moving it backwards and forwards. Make ventholes as be- 
fore. Grasp the drag between the two boards, turn it over, and 
rest it on the bottom board. Remove the moldboard and strike 
off the sand level with the top of the drag. Use care not to 
disturb the pattern. Smooth the surface with trowel or slick. 
Put on parting sand, using the same precaution as in the last 
exercise to blow off the excess sand and to avoid a layer along 
the edge of the pattern and on the drag. Place the cope in 
position, and set the plugs for the sprue and riser exactly as in 
Ex. 2, Fig. 46. Sift on enough sand to cover the pattern, 
pack around it with the fingers, shovel in the heap sand, and ram 
as directed under Ranuniiig, page 23. Make ventholes. Re- 
move the sprue and riser plugs. Make pouring basin (see l\ 
Fig. 3 1 ). Lift off the cope and rest it against the moldboard, 
as in Fig. 43. Wet around the pattern, drive in the draw spike, 
and lift the pattern. Cut the gate for sprue and riser as in the 
last exercise. Blow the dirt out of the sprue holes. Place the 
cope in position, weight or clamp, and pour. 

When several castings are to be made from a pattern like the 
one just described, two wooden strips just the height of half of 
the cylinder can be used in place of the wedges. 

Exercise 4. Cylinder {Split Pattern). 

Pattern : cylinder (split). 

Casting : cylinder. 

To make the mold : Place the half of the pattern which does 
not contain the dowel pins on the moldboard, flat face down, in 
a position similar to that in the last exercises. Place the drag 
in position similar to that in the last exercises, and riddle on 
sand till the pattern is covered ; then pack with the fingers. 
Fill the drag heaping full of heap sand free from foreign mat- 
ter ; ram ; strike off level, and seat the bottom board. Replace 
the bottom board and turn the drag over. (All of these steps 
are to be performed as described under previous exercises.) 
Remove the moldboard and smooth the joint with slick or 



40 



ELEMENTARY FOUNDRY PRACTICE 



trowel. Put on the other half of the pattern and make the part- 
ing, sifting on the parting sand and observing the precautions 
noted in the last two exercises. Place plugs for sprue and 
riser. Riddle on sand; pack with the fingers; fill with heap 
sand and ram. Vent ; remove plugs ; make pouring basins ; 
cut gates ; weight and pour, exactly as in the last exercise. 

Exercise 5. Application of Principles, Ex. 2 and 3.^ 

Pattern : handwheel (circular rim). 

Casting: handwheel. 

This pattern can be placed in the sand as directed under 
Ex. 2 or 3. In this case make it by paring down, as in Ex. 2. 

To make the mold : Select a flask quite a little larger than 
the diameter of the wheel. Place the pattern on the mold- 
board at the center. Place the drag in position. Riddle enough 
sand to cover the pattern and pack with the fingers. Fill the 




>•■^*^'•'^^•^'•^>v■v^>.Vf■•;■^/•:;;^^;■^.iV■i^;•<:.•J'•>':;■.^','. 






Fig. 48. 

drag with heap sand ; ram ; level off ; vent and turn as in 
Ex. 2. Pare the sand away to the center of the rim, making as 
gradual a slope as possible. With the foot of a lifter pack the 
sand between the arms down to their center line. Make part- 
ing ; place on cope, and set the sprue plug on the hub of the 
wheel, as shown in Fig. 48. Riddle on enough sand to cover 
the pattern; pack with fingers; shovel in heap sand; ram; 
vent; make pouring basin, and remove sprue plug as in 
Ex. 2. (As the sprue plug rested on the pattern, the hole left 
by its removal will open directly into the mold, so no gate 
needs to be cut.) Weight or clamp and pour. 

1 Various other patterns of this type will suggest themselves to be tried, either by 
paring down to the center line or wedging up the drag. 



CHAPTER V 




MATCHES 

A match is a mold used as a moldboard into which the pat- 
tern is inserted to its parting line (Fig. 49). 

A match is often used for patterns, such as Ex. 2, 3, 
and 5. Matches are made of sand, oil, or plaster of Paris. 
A sand match is used when only a few castings are needed. 
When it is desirable to keep the match for any length of time, 
an oil match is made, and if it is to be used indefinitely, it 
should be made of plaster of Paris. A match is made in a 
shallow frame the 
size of the flask to 
be used. It should 
have sockets to en- 
gage the cope pins. 
A bottom board 

should be securely Fig. 49. 

fastened to the frame. The oil and plaster of Paris matches, 
when not in use, should be stored in a place where they will 
not be injured, and the pattern should be left in the oil match 
to prevent the match from shrinking. 

Exercise 6. Green-sand MatcJi. 

Pattern : solid cylinder. 

To make the match: Fill the frame with riddled moldino- 
sand and pack it very solidly. Strike off the face or joint with 
a straight edge; flat and even with the edges of the frame. 
Bed the pattern in about the same relative position as shown in 
Fig- 17^ by driving it into the sand to its exact center. Smooth 
the whole surface with a slick or trowel. Draw the pattern to 
test correctness of the work. Replace the pattern and put on 
the parting sand. 

41 



42 ELEMENTARY FOUNDRY PRACTICE 

This match can now be used in place of the moldboard, by- 
placing the drag on it and filling and ramming as in Ex. 2 or 3. 
When the drag is turned over and the match is removed, all is 
ready for putting on the parting sand and proceeding with the 
cope. A match of this kind can be used several times, thereby 
saving considerable time. 

Exercise 7. Oil Match. 

Pattern : solid cylinder. 

To make oil match : Measure out enough burnt sand (or 
parting sand) to half fill the match frame. Thoroughly mix 
with the burnt sand an equal quantity of new molding sand and 
one fortieth litharge, and pass this mixture through a fine riddle 
while dry. Moisten this mixture of sand and litharge with 
boiled linseed oil and mix well, until the whole mass is of the 
consistency of well-tempered molding sand. (If too dry, it will 
crumble easily ; if too wet, it will take a long time to dry or 
become hard enough for use.) Ram this tempered mixture 
into the frame and strike off the surface level with the frame, 
and smooth. Bed the pattern, in the same position as in the 
green-sand match, to the parting line. Lay a few brads in the 
sand, close to the pattern, at points where the match is likely to 
become injured by wear; press them into the sand with the 
finger and smooth the surface with slick. ^ 

Draw the pattern out to test the parting, return the pattern, 
and set the match in a moderately warm place to dry. This 
will require from one to two days. When thoroughly dry, 
remove the pattern and apply two coats of thin shellac. 

This match is used exactly as a moldboard or the green-sand 
match, except that no parting sand is needed as in the case of 
the green sand match. 

Exercise 8. Plaster of Paris Match. 

Pattern : solid cylinder. 

To make plaster of Paris match : First make green-sand 
match as described in Ex. 6. Place a frame similar to the one 

^ These brads help to hold the sand firmly about the pattern. 



MATCHES 43 

used for the green-sand match but without bottom board,^ bottom 
side up, over the match, and securely fasten. Place the pattern 
in position in the sand match.^ Make a thick mixture of plaster 
of Paris and water, and fill the frame level full of the mixture. 
When the plaster has set, place the bottom board in position 
and securely fasten it. Remove the sand match and pattern. 
Remove any sand that may adhere to the plaster with a brush 
or wash with a little water. The match is now ready for use 
exactly similar to the oil match. 

1 A bottom board can be used if it is securely fastened to the frame, and a hole 
made through it, to pour the plaster through. 

- The pattern should be given a coating of light machine oil to prevent the 
plaster adhering to it. 



CHAPTER VI 



Gland. 



MOLDING EXERCISES WITH GREEN-SAND CORES 

Green-sand Core. — When a pattern is so formed that the 
sand of the mold is left in such a way as to form a hole or hol- 
low in the casting, the sand so left is called a green-sand core. 
Exercise 9. Simple Green-sand Core. 
Pattern ; 
Casting 

This pattern is made with two tapers to give it draft : one 
on the outside with the larger dimension at the flange end, 

„, ,, the other on the inside with 
-^ ^^^^^^^^i^^'-'^^:^^^''O^^M<^. ^ the smaller dimension at the 

y flange end. The outside ta- 

^;j.'v,-r:.:iv:-v P^^ allows the pattern to be 

'/.r--."'';-t^>^VV/ '[^ removed from the sand, while 

the inside taper allows the 

inner core of sand (the green- 



FiG. 50. 

sand core) to slip through the pattern. 

To make the mold : Place the pattern on the moldboard 
with flange or largest outside end on the board, as shown in 
Fig. 50. Place the drag in position. Riddle enough sand to 
cover pattern. With the fin- 
gers pack the sand about the 
pattern, and press it into the 
hole. Care must be taken 
that the top sand in the hole 
is loose enough to adhere to 
the sand to be added. Fill 
the remainder of the drag; 

ram and vent as in previous Fig. 51. 

44 




MOLDING EXERCISES WITH GREEN-SAND CORES 



45 



r^rauj Sp/Ho. 
















/ 



Fig. 52. 



work. Care must be taken to have a good union of the sand 
in the hole with that in the rest of the drag. Turn the drag 
over ; make parting ; set sprue 
plug ^ in position shown in 
Fig. 51, and finish the cope as 
in previous exercises. Re- 
move the cope, press a nail 
into the 'sand in the holes 
(Fig. 5 1 ) to strengthen the 
core, and anchor it to the rest 
of the sand in the drag. Draw 
the pattern (Fig. 52) and finish 
by cutting gate and making 
pouring basin ; as in other 
exercises clamp and pour. 

Exercise i o. Grooved Pulley ( Two-part Flask). One roll over. 

Pattern ) ^ •, ,, 

^ . • Grooved pulley. 
Castmgl 

To make the mold : Select a flask quite a little larger than 
the pattern. Place the female part of the pattern on the mold- 
board as shown in Fig. 53. Place the drag in position; insert 
the sprue plug as shown at a, Fig. 53 ; fill ; ram and vent as in 

Ex. I. (The sprue plug must 
not project above the drag.) 
Turn the drag over in the 
usual way. With a trowel 
pare the sand down to the 
parting line of the edge of 
the pulley, as shown in Fig. 
54. Put on parting sand, taking care that none gets on the 
pattern. Place the male part of the pattern in position and 
build up the cheek, or green-sand core, as shown at b in Fig. 55. 
This is done by packing in riddled sand with the hands, and 
lightly slicking. Put parting sand on the exposed part of the 

^ Riser is not necessary in this case. 




Fig. 53. 



46 



ELEMENTARY FOUNDRY PRACTICE 



I 




i 



n^^sr 



Fig. 54- 



cheek. Place cope in position ; fill ; ram and vent as in other 

exercises. 

To draw the pattern : Lift off the cope. The cheek and pat- 
tern will remain on the drag as in Fig. 55. The half of the pattern 

is now removed as in previous 
exercises. Should the half 
pattern remain in the cope, as 
shown in Fig. 54, it can be 
removed in the usual way. 
Figure 56 shows the drag with 
the pattern removed. Dust on 

a little facing. Replace the cope; place bottom board on top; 

turn the flask over, remove the sprue plug and form pouring basin. 

Lift off the drag. The cheek will now remain on the cope and 

the remainder of the pattern can be drawn from the drag. Should 

the pattern remain on the 

cheek great care must be 

observed in driving the draw 

spike not to injure the cheek. 

Dust on facing; replace tht 

drag, which is now a cope ; 

clamp, etc., as in the previous 

exercises. Figure 57 shows 

mold ready for pouring. 
Exercise ii. Grooved 

Pulley {TJiree-pcD't Flask). 
Pattern : grooved pulley, 

same as in Ex. 10. 

Casting : same as from 

Ex. 10. 

To make the mold : Select a three-part flask in which the height 

of the cheek is equal to the distance between the parting lines of 

the pattern (Fig. 58) and considerably larger than the diameter. 

Place the cheek on the moldboard with the drag side up. Then 

place the pattern centrally in the cheek. With wedges raise the 




Fig. 55. 



A-.-:i.-A 




Fig. 56. 



MOLDING EXERCISES WITH GREEN-SAND CORES 



47 





cheek sothat its edges come to the parting Hnes of the pattern 
(Fig. 58). Fill with riddled sand, press well into the groove with 
the fingers, and then ram. 
Smooth the joint and make 
parting. Place the drag in 
position and ram and vent as 
usual. Turn the drag and 
cheek over. Smooth the joint 
and make parting. Place the 
cope in position. Set the 
sprue plug over the hub, and 
finish the cope in the usual ^' ^^' 

manner, as shown in Fig. 59. Remove the sprue plug and form 

pouring basin. 

To remove the pattern : Lift 
off the cope and cheek with- 
FiG. 58. out separating them. Draw 

the part of the pattern in the drag. Dust on facing. Replace 
the cope and cheek. Lift off 
the cope and remove the rest 
of the pattern. Should the 
pattern remain in the cheek, 
great care must be observed in 
driving in the draw spike not 
to injure the cheek. Dust on 
facing and replace the cope. 
Clamp and pour.^ 

Exercise 12. 
Cheek mid Cope. 

Pattern 1 

Casting/ 

To make the mold : Select a three-part flask of suitable size 
with a cheek of the same height as the pattern. Set the pattern 







f>^*V: 









H'---;-^>A- ^■-;k^^'^■■,'^^•.•1!.^'.V•^*>V>;-:^■'•^•'^'•■•-■• 
— ^v\-^Tf "^ *^ k3.v; 






Fig. sq. 

Column Base {Three-part Flask). Sprue in 



Column base. 



1 Other methods of making the grooved pulley should be discussed. 



48 



ELEMENTARY FOUNDRY PRACTICE 



^M 









I 






Fig. 6o. 



on the moldboard with the large face on the board. Place the 
cheek on the board with the drag side up. Put a sprue plug just 
the height of the cheek, at one side or in one corner, as shown 
at a, Fig. 6o. Ram up the cheek and sift parting sand over all 

exposed molding sand. Place 
the drag in position and ram 
and vent it in the usual way.' 
Turn the drag and cheek over 
and put parting sand on that 
portion of the mold between the pattern and the cheek frame. 
With a slick loosen up the top sand inside the pattern, so that 
there will be a good union when sand is added. Put on the cope, 
and set the sprue plug b about one inch from the plug a in the 
cheek (Fig. 6i). Ram, vent, and finish in the usual way. 

To remove the pattern: Draw the sprue plug b, Fig. 6i, and 
form the pouring basin. Place on bottom board and lift off the 
cope, and turn over and rest 
on the board. This must be 
done with great care, as the 
sand inside the pattern (green- 
sand core) will lift with the 
cope. Draw the sprue plug 
a from the cheek, draw the 
upper part of the pattern g, 
and dust on facing. Cut gate Fig. 6i. 

/and replace the cope. Lift off the cope and cheek, draw the 
remainder of the pattern c, and dust on facing. Replace the 
cope and cheek; clamp and pour.^ 

1 If the hanging portion of the cope (the part extending into the pattern) is very 
deep, it may be well to roll the complete flask over and draw the pattern by first lift- 
ing the drag and cheek, drawing part g of pattern, replacing drag and cheek, re- 
moving the drag and part c of pattern, replacing the drag and rolling flask back to 
pouring position, or by placing the top face of the pattern on the moldboard when 
making the mold. 




CHAPTER VII 

DRY CORES 

1. Dry cores consist of a mixture of a refractory sand and 
some binding material, molded in a core box, or swept by a 
sweep (Fig. 105) to the shape of a desired hole or cavity in a 
casting, and then baked. When placed in the mold, these cores 
prevent the metal from filling certain portions, and when burned 
by the heat of the metal, the core crumbles and leaves a hole in 
the casting. The cores may form recesses in, holes of any de- 
sired shape through, or they may hollow out the inside of a 
casting. The making of dry cores is a separate branch of 
the foundry business. 

In core making, as in green-sand molding, the principal ma- 
terial is sand. In green-sand molding the grains of sand are 
held together by the alumina. In dry core work the grains of 
sand are held together by the binder which the molder intro- 
duces, the amount and kind of which he controls as best suits 
his use and convenience. A naturally free sand must be used 
as a base. A sand containing alumina would cake in baking, 
and also when in contact with the hot metal, thus becoming very 
hard to remove from the casting. To this free sand some or- 
ganic material possessing binding qualities must be added. 
This holds the grains of sand together until the metal has 
formed about the core. At the same time that the metal is 
cooling, the binder should be burning out. The core can then 
be easily removed. 

2. Binders. — The materials most generally used and answer- 
ing the above requirements are : 

Flour. The most universal material is wheat flour, which acts 
in the core as it acts in bread. 

E 49 



50 ELEMENTARY FOUNDRY PRACTICE 

Rosin. A hard vegetable gum which, when finely powdered 
and mixed with the sand, has a strong binding action; this is 
due to the fact that it melts in the oven, forming a coating over 
the sand grains which cements them together upon cooling. 

Linseed oil, when mixed with sand, acts very much like the 
rosin. It is also used in connection with flour when a very 
strong core is wanted. 

Glite, when dissolved in water and used to temper the sand, 
makes a good binder. 

Molasses water is used for wetting the sand in making small 
cores. It is made by mixing one cup of molasses with a pail of 
water. 

Clay zvash is used as a base for blacking. (See page 8.) 

Mamifactiired binders, both in liquid and in dry forms, can be 
obtained on the market. Some claim that a better and cheaper 
core can be made by their use. 

3. Core Materials Other than Binders. 

Soft iron wire in various sizes, usually not smaller than No. i6. 

Bar iron in sizes from | inch to | inch according to the work 
the foundry handles. 

Gas pipes of various sizes are used for strengthening cores 
in some classes of work. 

Wooden frames wrapped with straw or hay rope, plastered 
with a thick clay wash, are used on large work to strengthen 
cores. 

Cinders are used in large cores to make venting easier, also to 
prevent cracking due to expansion. 

Wax which will melt and run between the sand grains on 
baking, leaving a passage through which the gas can escape, is 
very often used. 

Charcoal or graphite washes are apphed to the cores before 
using, by dipping the cores or painting them. 

Composition and Making of Cores. — As mentioned before 
cores are for forming holes or cavities in castings. In order to 
effect this result the core usually spans an opening in the sand. 



DRY CORES 



SI 



The core must therefore be strong enough to hold its weight 
when supported at its ends, and also to withstand the force 
of the metal rushing in to fill the mold. This condition is 
met by properly proportioning the mixture of free sand and 
binder, and by the use of wires or of iron rods in the core. 

The binder serves not only to keep the core in shape before 
baking, but to insure its strength after baking. Too much 
binder causes the core to sag before it is baked, and also to 
" blow " (give off more gas than the vent can take care of) when 
the metal surrounds it. When too little binder is used, the core 
is not strong enough to do its work. It " cuts " when the metal 
is poured. 

As sands vary so greatly, no exact proportions can be given 
for all cases. The following will serve as a guide : 



Composition : Small Cores 

Beach sand ..... 
Flour ..... 

Temper with molasses or beer. 

Large Cores 

Sharp sand ...... 

Strong molding sand ... 

Flour 

Temper with clay wash. 

For Small Complicated Cores 

1. Beach sand 
Fire sand 
Rosin 
Flour 

2. Beach sand 
Molding sand 
Flour 
Linseed oil 



8 parts 
I part 



8 parts 

2 parts 

\\ parts 



15 parts 


15 parts 


2 parts 


I part 


15 parts 


5 parts 


2 parts 


I part 



52 



ELEMENTARY FOUNDRY PRACTICE 



MAKING 




Fig. 62. 



Tools. — The tools used in core making are the same as those 
used in the foundry. The small trowel, however, almost entirely 

replaces the sHck. A small 
iron rod is used on small 
work as a rammer. A spray- 
ing can (Fig. 62) is used to 
spray molasses water over 
the cores.^ 

Mixing. — The proper 
amount and proportion of 
sand and other constituents 
should first be thoroughly 
mixed dry, or until the mixture becomes uniform in color, and 
then formed into a circular heap with a crater in the center. 
Into this crater is introduced water, beer, molasses water, or oil. 
The sides of the crater are now turned in, so the tempering liquid 
moistens the mixture. The mass must now be thoroughly worked 
until the tempering liquid is evenly distributed. Only enough 
liquid is to be added to cause cohesion of the sand mixture ; if too 
wet, the core will stick to the core box. When tempered, the 
mixture is pressed into core boxes as explained later under the 
various exercises or swept into shape by means of forms and 
sweeps. When large quantities of cylindrical cores are used, 
they are made with machines. The mixture is placed in a 
hopper and forced from this hopper through a former as a long, 
cylindrical core which can be cut to the desired length. A large 
variation in the diameter can be obtained from each machine by 
changing the formers. 

Baking. — As soon as a core is made it should be placed in 
an oven and baked. If allowed to stand for any length of time 
in the air, it becomes air dried and crumbles. The length of 
time it takes to bake a core depends on the size of the core and 

^ One or two spray cans will supply a large class. 



DRY CORES 



53 



the heat; usually from one half hour to two hours is required. 
A core must not be placed in the direct path of flames as they 
char the binder and make the core useless. 

Oven. — An oven for baking cores is a necessary adjunct to 
every foundry. In foundries doing only light work, a small oven 




Fig. 63. 

similar to the one shown in Fig. 63 is used. These ovens are 
made of brick or of iron. The iron ones are portable. They 
consist of an ash pit, a fireplace, and an oven. The front of 
the oven is a series of doors, to which shelves are attached. 
These shelves are perforated to allow the heat to pass from one 
to the other. On the back of the shelf is a plate the size of the 
door. When the door is opened and the shelf drawn out, the 



54 ELEMENTARY FOUNDRY PR.\CTICE 

back plate closes the opening. In this way the loss of heat is 
prevented. In a foundry doing large work, an oven will be 
found capable of taking the largest pieces made. Very large 
ovens are fitted with tracks so that the pieces can be run in and 
out on cars. The portable oven is the most desirable for school 
use. 

Finishing. — Before a core is used it should be given a coat 
of blacking. This will give the core a smoother surface and 
leave a smoother, better hole in the casting. 

A good blacking for light cores is made as follows: Mix 
one cup of molasses in a pail of water ; into this stir powdered 
charcoal until an even coating of black will be deposited on the 
core when dipped thereinto. 

For heavy work, take one part of charcoal and two parts of 
graphite and mix with a thick clay wash. The light cores can 
be dipped into the blacking. In the case of large cores, the 
blacking should be put on with a brush. 



CHAPTER VIII 

MOLDING EXERCISES WITH DRY CORES 

In the preceding chapter the composition, making, and 
baking of dry cores was given in a general way. In this 
chapter a few exercises will be taken up to bring out special 
ways of venting, forming, and setting some of the simpler 
forms. 

Venting Cores. — The heat of the metal, by burning the 
binders and other constituents of cores, forms gas. This gas, 
as well as that in the sand, must be conducted out of the mold. 
If not properly carried off, it will force its way out at the point 
of least resistance. This is often through the molten metal. 
When it escapes thus, the casting is spoiled, becoming spongy, 
or full of holes ; and sometimes it is even blown out of the 
mold. 

A core must therefore be made with vents to carry the gas 
to a point where it can pass off through the sand of the mold. 
When the metal completely surrounds a core except at the prints, 
there must be ample passages to these prints through the core, 
and the sand of the mold next to the prints must be well 
vented. When the metal touches but one side of a core, no 
special venting is needed. The same is true of a small core 
partly surrounded with metal. 

Setting Cores. — The setting of dry cores may be classed 
under two heads: (A) setting in prints where the print does the 
holding; (B) setting in prints where the print locates only and 
the core is held by chaplets or other means. 

{A) Cores held by Prints. — The setting of a simple core 
when the pattern has prints is a simple matter. The core is 
vented by running a hole through it to the part that fits in the 

55 




56 ELEMENTARY FOUNDRY PRACTICE 

print. The core is placed in the print depression in the drag 
and the cope placed in position. This anchors the core in 
position, and the gases will pass off through the sand at the 
prints. When a core is set on end in the drag and projects into 
the cope, care must be taken that it enters the print recess in 
the cope properly or the mold will be broken. 

Exercise 13. Simple StraigJit D}y Core. Held by prints. 

Pattern : gland (split pattern with prints). 

Core : straight core (made in halves). 

Casting : gland. ^ 

Core Box. — The core box is shown in Fig. 64, a being a 

longitudinal section through the center and b a transverse section 

^_^^ along the line e-e. 

^NS^^ To make the core : The core for 

^ this exercise can be made in two 

^^'^- ^'*- ways : {a) in halves, {b) solid. 

{a) Mix 8 parts of sharp sand with i part of flour (receipt i, 
page 51) as directed in Chapter VII, page 52, and temper 
with molasses water,^ care being taken not to get the mixture too 
wet. Fill the core box heaping full of the mixture and press it 
in quite hard with the fingers. (A core must be rammed harder 
than a mold, but not so hard as to stick to the box nor so com- 
pactly as not to vent.) Smooth the face level with the top of 
the box with a trowel. Invert on a sheet-iron plate heavy 
enough not to bend. Rap the box slightly to loosen the core, 
and remove the box, leaving the core on the plate. (Two of 
these half cores are needed, but at least four should be made to 
replace any that maybe broken.) Spray with molasses water 
and place in the oven to bake. When baked, take two of these 
half cores, rub the flat faces together to insure perfect contact over 
the entire surface. Cut a groove down the center of each from 



1 The student will note that this casting and the one from Ex. 9 are similar and for 
the same use. 

2 To make molasses water, add 2 tablespoonfuls of molasses to I quart of water 
and stir until thoroughly mixed. 



MOLDING EXERCISES WITH DRY CORES 



57 



end to end. Paste the halves together with flour paste, taking 
care that no paste gets into the vent groove, and give a coating 
of blacking, {Sqq Blacking, page 54.) 

{b) Follow the directions given under (a) for mixture. To fill 
the box clamp or hold the halves tightly together, stand the box 
on end on a metal plate, and force the core mixture into the 
hole ; ram it solid with a |-inch 
iron rod till full ; strike off the 
ends smooth ; run a wire through 
the middle of the core from end 
to end to form the vent passage. 
Rap the box lightly and remove one half of it. Invert the half 
containing the core on a plate and roll the core from the box, 
as shown in Fig. 65. A large core made in this way is likely to 
become flattened on one side because of its weight. 

To make the mold: Make the mold as in Ex. 4, observ- 
ing all the directions for ramming, venting, etc. Set the sprue 
plug as shown in Fig. 66. 




Fig. 65. 











To set the core : See that the core is cool. A core must not 
be set into a mold hot, as this will cause sweating. Carefully 
place the core in the depressions in the drag left by the core 
prints. See that the core is a snug fit. If the core does not fit 
the print, make it do so by fihng the core if it is too large or 
too long, or by filling the depression with sand if the core is too 
small. Vent the cope well from the ends of the core as shown 



58 



ELEMENTARY FOUNDRY PRACTICE 




in Fig. 66. Place the cope in 
position, clamp, and pour. 

This pattern can be made 
solid, in which case the mold 
would be made as in Ex. 2 or 3. 
Fig. 67. The core for that exercise can 

be made in one piece, with a box, as shown in Fig. 6"]. 

Exercise 14. Setting Bolt Hole Core and Core below the 
Surface. 

Pattern : bracket. 

Cores : core and filling piece combined (pocket core), b, 
Fig. 72, and short cylindrical core. 

Casting : bracket with a cored hole in each part. 
To make the cores: Use the same mixture as in Ex. 13. 
Core a. Hold the halves of the core box (Fig. 68) tightly to- 
gether with the hands or a clamp. Ram 
the core mixture into the box with a |-inch 
iron rod and smooth off end. Rap the box 
hghtly; stand it on end and separate the 
halves, leaving the core standing on end, 
as shown in Fig. 69 ; spray with molasses 
water and bake. Core /;, core box. Fig. 
70; « is the plan of the box and b the 
elevation of one half. It will be noticed 
that the box separates into halves along the line c-d. Hold the 
halves tightly together and fill with core mixture like that used 

for core a. With a f-inch 
rod ram the mixture solidly 
into the round portion, and 
with a bench rammer ram 
the balance of the core ; 
run a wire or small nail 
into the round portion, to 
strengthen it, as shown in Fig. 71. Smooth off the face and 
end of the core even and level with the box. Invert on iron 





Fig. 69. 



MOLDING EXERCISES WITH DRY CORES 



59 




- 








^^3 


^^^^^^^ 



Fig. 70. 



plate,^ rap lightly, and separate the halves of 
the box. Spray with molasses water and 
bake. Give each core a coating of blacking. ^ 
To make the mold : Place the pattern with ci 
the face c. Fig. 72, on the moldboard, and 
make the mold in a manner similar to Ex. i. 
Place the sprue so that the gate can be cut A 
either in the end, as shown in Fig. 72, or 
to the side of the mold. 

To set the cores : Core a is stood on end in the hole left by 
the print on the pattern. Core b is placed in the depression left 
by print. Care must be taken that the print 
holes are filled by the core. If the cores do not 
fit snugly, pack a little molding sand around 
them, and sUck over to prevent the metal from 
flowing where it is not wanted. See that the 
tops of the cores come flush with the joint line. Make a vent- 
hole from the center of each core print before the core is set. 



^A/a/7 



■: - 




rr. 


:®3S<SSV; 


¥»^ 




'^1 


f'» 


^*^?;r;r 



Fig. 71. 





Place the cope in position. This will anchor the cores so that 
they will not rise when the mold is poured. Clamp and pour. 

Exercise 15. Balanced Core. 

A balanced core is one where the part resting in the print has 

1 All plates should be of about No. lo iron, so they will not bend when handled. 



6o 



ELEMENTARY FOUNDRY PRACTICE 



weight enough to balance and hold in position an overhanging, 
unsupported end. (In Fig. J"^ the hole extends into the cast- 
ing, but not all the way through it. This gives the core but one 
support, which makes it necessary to extend it far enough back 
from the mold to balance the weight of the overhanging part.) 

Pattern : lathe chuck for short bars. 

Cores : cylindrical. 

To make the core : Make the core of the same composition 
as core ^, Ex. 13, and in a similar manner. Vent the core the 
entire length except for a short distance at the end which pro- 
















\Ayi :^/\ 



Fig. 73. 



i 



-r 



> I 
• I 

/.In ' I 






\ 

-J. 



jects into the mold. (If the vent is made by running a vent wire 
through the core, the vent at the end that projects into the mold 
can be stopped up with a little fire clay.) 

To make the mold : If a split pattern is used, make the mold 
similar to Ex. 4. If a solid pattern is used, make the mold 
similar to Ex. 2 or 3. 

To set the core : Place the core in the print depression. 
Care must be taken that it is a good fit in the print and that it 
projects into the mold exactly the right distance.^ See that the 
cope is well vented from the end of the core (Fig. 73). Close, 
clamp, and pour. 

Exercise 16. Setting Core belozv the Surface {by Stopping off). 

Pattern : bearing. 

1 It is well for the core to have a head like that shown at a, Fig, 73, as it not 
only adds extra weight to balance the core but locates it definitely. 



MOLDING EXERCISES WITH DRY CORES 6 1 

Core : straight cylindrical. 

Casting : bearing with cored hole. 

To make the mold : Place the flat face of the pattern on the 
moldboard, and fill, ram, and vent both cope and drag in a 
manner similar to Ex. i. Make vents from each print de- 
pression. The sprue should be placed so that the gate can be 
cut from the end of the mold or one side near the end.^ 

To set the core : Place the core c in the depressions as shown 
in Fig. 74. Stop off the depressions b above the core by holding 




I>'IG. 74. 

the stopping-off piece a over the core, and against the end face 
of the mold. Fill with molding sand the space b over the core, 
and slick even with the joint. Close the mold clamp; and pour. 

Exercise 17. Segment Core. 

Pattern : groove pulley. 

Core : segment core. 

Segment Core. — A segment core is one built up of segments 
of a circle ; a. Fig. 75, shows one segment or one sixth of a core. 
Each segment is made of two halves like section a, Fig. 75. 

To make the core : ^ To the required amount of sharp sand 
add linseed oil and work in thoroughly until it becomes saturated. 
This will be when the oil shows slightly on the finger nails when 

1 In a laTge casting the sprue can be placed at the side about the center and gates 
cut to the side near each end. 

- This core is made with linseed oil, not because it is necessary that a segment 
core should be tempered this way, but to show the use of linseed oil in core work. 



62 



ELEMENTARY FOUNDRY PRACTICE 



the hands are pressed into the sand. The oil should be intro- 
duced in the same manner as tempering water was in previous 
exercises, — by pouring it into a crater and then turning in the 





a 



Fig. 75. 



-2J 



5^ 



\ 



f-.r!,\-vv/.;.,i;-iv.-- 

■:^ -.•'>■ rr^v- .-.•>• 









sand from the sides. The sand should then be worked with the 
hands and more oil added, if necessary, until properly tempered. 
Fill the core box in a way similar to a, Ex. 13. Remove to 
plate and bake. Twelve cores will be necessary. 

To make the mold : Place the pattern on the moldboard and 
ram the drag as in Ex. i. Turn the drag over and cut the sand 
away to the line a, Fig. 'j6. Make parting, place the cope in 

position, and set the sprue 
plug on the hub (Fig. 76). 
Ram in the usual way and 
remove the pattern. 

To set the core : Paste to- 
gether two half cores (being 
sure the ends are even). Put 
a little paste on the ends of 
each pair and set them around 
the mold in the core print, being sure they fit snugly, and touch 
the mold at the back of the print. Close, clamp, and pour. 

Segment cores are used on large work mostly. On small 
work the core is usually made in halves. Each half has the 
same section as the segment core, but is a complete circle. 
Exercise 18. Hollow Core. 
Pattern : cover with ornament on top. 
Core : hollow core for ornament. 



L^JVxl 



Fig. 76. 



MOLDING EXERCISES WITH DRY CORES 



63 



The projecting ornament at the top is of such a shape that it 
will not draw out of the sand in the position the cover must 
be molded. In order that the casting may be made with this 
ornament, the pattern has a core print at the 



place where the ornament is to be. A core is 
used whose outside shape and dimensions are E^//y/)^»)^>^ >77; 
the same as the print, and whose inside is hoi- I'ig. 77- 

lowed to the shape of the ornament. Figure yy shows a cross 
section of the box, which makes half the core. 

To make the core : Measure out enough sand and flour (in 
correct proportion) to make about three half cores; add to this 
a small handful of finely powdered rosin. Mix thoroughly 

until all is of a uniform color 
and then temper, as before, 
with molasses water. Fill the 
box by ramming in the core 
mixture as before. Invert on 
plate, rap the box lightly to 
loosen the core, and remove 
it. When baked, give the 
inside a coating of blacking and paste the halves together. 

To make the mold : Place on the moldboard as shown in 
Fig. 78. Ram the drag in the usual manner. This pattern is 
easily broken, so it must be handled carefully. Turn the drag 
over. Put on the cope and parting sand. Set plugs for riser 
a, and runner d, Fig. 79, and ram in usual manner. Lift 
the cope and remove the pat- 




l/J%'\ 



Fig. 78. 



tern. Set core in print de- 
pression. The core must fit 
tightly in the depression, 
come flush with the bottom 
of the mold, and all openings 
between core and mold filled 
with molding sand. Replace 
cope ; clamp and pour. 



"^'i^&^'M^i^i^^. 



6m 



■•■> > 



• JVC ----- v-^- - '-•■ ; *» - v'' k ;;^>-.v ■;■ -■ JA-.-''^ r. :. 
^::V^S:■■-:■:>;^•2 ^":^^v;^:'C<^;>:y.r■:-^::-^■<-::| 



"E^sr 



Fig. 79. 



64 ELEMENTARY FOUNDRY PRACTICE 

Note. — A large pattern of this shape would require a special cope with 
crossbars and gaggers to support the sand that extends into the pattern. 

{B) Cores located by Prints and held by Chaplets or Other 
Means. — The cores just taken up are held m position by prints. 
There are many cases, however, where the prints are merely for 
locating the core. It then becomes necessary to use some 
device to hold the core in place while the metal is being poured. 
Some small cores are held by placing nails slantingly into the 
sand, the heads bearing against the core to hold it. Cores rest- 
ing in the drag are held by chaplets as shown at f, g, and k in 
Fig. 81. Other cores have prints in the cope for locating them, 
but have none in the drag for support. In this case they are 
hung by wires (Fig, 80). The wire holds the weight of the 
core till the metal is poured. The metal then forces and holds 
the core into the print. 

Chaplets are iron supports used to hold cores in position, 
when prints cannot be used. Chaplets are made in an almost 
endless variety of shapes and sizes. However, there are two 
general types, — single headed and double headed. A single- 
headed chaplet is shown at a and a doubled-headed at b in 
Fig. 80. The stems are burred so that the metal will grip the 
chaplets firmly. The stem of a single-headed chaplet may 
be either blunt or pointed. Stems shown at c to which heads 
of any size or shape may have been riveted make most useful 
chaplets. The chaplet and stand at d are also very useful. 
They allow great flexibility, since any variety of heads may be 
placed in the stand. ^ is a double square head chaplet of 
gray iron. These chaplets fuse well into the hot iron ; conse- 
quently they do not cause blowholes and leave very little 
blotch on the surface, g, h, i, J, and k show the " Peer- 
less Perforated Chaplet," used on all classes of castings re- 
quiring small cores. They are made of perforated, tin-plated 
sheet metal, insuring perfect ventilation of the chaplet, elimi- 
nating all possibilities of blowholes, air pockets, chills, etc., 
forming a perfect union with the molten metal, thereby giving 



MOLDING EXERCISES WITH DRY CORES 



65 








^^ 




Of 






Fig. 8o. 



66 



ELEMENTARY FOUNDRY PRACTICE 



a pressure tight joint, g and i are used for cast pipe; k 
for flat straight work ; J for fiat round or straight work. 
They can be bent with the fingers, as in k, to fit the mold ; 
/ is a stem for a double-head chaplet ; m and n are pressed 
tin shell chaplets. They form a perfect amalgamation and 
union with the cast metal. ^ is a special cast-iron shape and 
/ is a double square-headed chaplet with point. 



fTH 






-SnI 







■E33J 



F^rr 



Fig. 8i. 



Chaplets weaken a casting, and therefore their use should be 
avoided as far as possible. When they must be used, care 
should be taken to place them where this effect will be reduced 
to a minimum. 

Chaplets weaken a casting in three ways : 

(i) By the introduction of a foreign metal ; 

(2) By the formation of porous spots about the chaplet, and 

(3) By not fusing with the metal. 

The first cannot be avoided, but can be reduced by proper de- 
sign. The second can be prevented by using a tinned chaplet 



MOLDING EXERCISES WITH DRY CORES 



67 



or placing red lead on the chaplet, and by keeping it free from 
moisture. The third can be avoided by roughing or notching 
the stem so the metal will take a close hold. 

Setting Chaplets. — It is important that a chaplet be set cor- 
rectly or its efficiency will be reduced. It must be wedged so 
as to give a solid bearing of the wedge on the stem of the 
chaplet, and of the chaplet on the core. The head should be 
bent to conform to the shape of the core as at c. When a 
bottom board is used, a drag chaplet may have a pointed stem 
long enough to drive into the board, as at / and e. A block of 
wood is sometimes rammed into the sand and the chaplet driven 
into it, as at Ji. At g are shown the uses of a chaplet and stand. 

Venting and setting of different cores will be taken up under 
the various exercises following. 

Exercise 19. Nailed Core. 

Pattern : small rectangular block. 

Core : T-section. 

Casting: block with T-slot across bottom. 

To make the core : Make the core of the usual sand-and- 
flour mixture ; fill the box ; remove from the box on iron plate, 
and bake. 

To make the mold : Make the mold exactly as in Ex. i. 

To set the core : Set the core on the bottom of the mold ; 
see that it fits tightly against 
the ends of the mold. (This 
core should be made a little 
long so that the ends can be 
filed off to insure a fit.) Press 
nails slantingly into the sand 
so that their heads will pro- 
ject slightly over the core, as 
shown in Fig. 82. The heads 
of the nails prevent the core from floating out of position as 
the mold is poured. No special venting is necessary. Close, 
clamp, and pour. 



t 






R 






'^•^"^v■-;-..^:/...■•,^-C' <?.'': c^ .' ;,'■.:■ •.-.'•.•• .-cv, v. i;.-/ 



Fig. 82. 



68 



ELEMENTARY FOUNDRY PRACTICE 



Exercise 20. Nailing Core to Bottom Board. 

Pattern : rectangular block with print on one side. 

Core : square core. 

Casting : rectangular block with square hole partly through it. 

To make the core : Make the core out of the ordinary mix- 
ture. Ram in the core box, strike off level. Make a hole com- 
pletely through the core a little larger than the nail or chaplet 
to be used. (The hole can be enlarged by moving the nail back- 
wards and forwards and around in a circle a few times.) Re- 
move the nail from the core and the core from the box, and bake. 










t 



VP^ 



Fig. 83. 



i-^^^J 



To make the mold: Make the mold as in Ex. i, placing 
the pattern on the board with the core print up. Vent well the 
sand in the drag around the core print. 

To set the core : Place the core in the depression. Press a 
nail or chaplet with pointed stem through the hole in the core 
and into the bottom board (Fig. 83). Fill in the opening in the 
core above the nail with a little molding sand. Close the mold ; 
clamp and pour. 

Exercise 21. Hanging Core. 

Pattern: same as Ex. 20 except that the draft is in the op- 
posite direction. 



MOLDING EXERCISES WITH DRY CORES 



69 



Core : square core, made in same box as Ex. 22. 

Casting : same as Ex. 20. 

To make the core : Make the core, using linseed oil for 
binder as in Ex. 17. Fill the core box about half full. Take a 
piece of No. 18 wire about twice as long as the core is high, bend 
it in the middle so as to leave a small loop, twist the wire a 
length equal to the height of the core box yet to be filled, and 
bend the remainder of the wire at right angles to the twisted 
portions. If there is too much wire, the ends can be cut off or 
coiled up. Place wire in the core box, resting the bent or coiled 
ends on the sand already in the box and so the loop will be in 
the center of the print and projecting a little above, then finish 
filling the box. Remove the core, and bake. 













i 



Fig. 84. 



-^^zz 



To make the mold : Make the mold the same as Ex. i, placing 
the core print on the moldboard. Vent the cope above the core. 

To set the core : With a vent wire make a small hole in the 
cope at the center of the print depression, slightly enlarging 
at a. Fig. 84. Attach a wire to the loop in the core, and twist 
it for a length about equal to the depth of the cope. Pass this 
wire through the hole. Place a bar b across the cope and attach 



7° 



ELEMENTARY FOUNDRY PRACTICE 



the wire. With wedges between the bar b and the edges of the 
cope draw the core up tightly into the print. Close the mold; 
clamp and pour. 

Note. — The use of this core prevents a deep lift of the cope. 

Exercise 22. Anchoring Core with Chaplets. 

Pattern : rectangular block. 

Core : T-shaped, made in two parts. 

Casting : rectangular block with T-slots on sides. 





To make the core : This core is made up of two parts, as 
shown at a and b, Fig. 85, in boxes of which c and d show sec- 
tions. Make up a core mixture using rosin, and make and bake 




iM&M!^<MM<m^ 






K^-^l 



^x^ 



Fig. 86. 



two cores from each box. Rub the flat faces of each part to- 
gether, to make a good joint, and paste the parts together. 
To make the mold: Make the mold exactly like Ex. i. 



MOLDING EXERCISES WITH DRY CORES 7 1 

To set the cores : Drive pointed chaplets a-a, Fig. Z6, into 
the bottom board, letting them extend up to such a height that 
the cores c-c, when resting on their heads, are in the proper posi- 
tion. Put the cores in the print depressions and on chaplets 
a-a. Place double-headed chaplets on upper side of core as at b. 
The chaplets must be just long enough to come to the joint line 
of the flask. (By means of the chaplets and the part of the core 
in the print, the cope sand prevents the metal from floating the 
core.) Close the mold; clamp and pour. 

Exercise 23. 

Repeat Ex. 22, using chaplets that come up through the cope 
and requiring wedging, as shown at a in Fig. 81, page 66. 



CHAPTER IX 

MISCELLANEOUS EXERCISES 

There are a few exercises involving important principles that 
either do not fall directly under the headings so far dis- 
cussed or else were too difficult to make with the practice had 
when the general class under which they fall was discussed. 

GATED PATTERNS 

When a great many small castings of one kind are wanted, 
time and labor can be saved by the use of a gated pattern. A 
gated pattern is one composed of several similar patterns con- 
nected in such a way as to form 
a single pattern. The connect- 
ing pieces leave impressions in 
the sand, which form the gates 
for the individual patterns. A 
gated pattern is usually made of 
Fig. 87. metal to make it more durable. 

A tapped hole for the insertion of the draw screw is made in 
the center of the patterns. Two steady pins are usually placed 
on the drag side to steady the pattern as it is lifted from the 
mold. A gated pattern with flat joint should have a perfectly 
flat moldboard. When it has an irregular joint, a match should 
be used. 

Exercise 24. Gated Pattern {Plain Moldboard). 
Pattern : Fig. 87. 
Castings : hexagon nuts. 

To make the mold : Place the pattern in the sand as in Ex. i. 
Care must be taken, however, to have a perfectly level mold- 
board, to avoid springing the pattern. 

72 




MISCELLANEOUS EXERCISES 



73 



Exercise 25. Gated Pattern {molded with Match Board). 

Pattern : Fig. ^Z. 

Casting : bushings. 

To make the mold : Make 
oil match as described in Ex. 7. 
Use this match in place of a 
moldboard and make mold as 
in previous exercises. Fig. 88. 



© 



Cup-shaped cap with round projecting handles. 



IRREGULAR PARTING 

Often a pattern having some projecting part can be molded by 
making the parting surface an irregular surface. 

Exercise 26. Mold xvith Irregular Parting. 
Pattern \ 
Casting] 

To make the mold : Place the pattern on the moldboard and 

support it with blocks, a-a. 
Fig. 89. Wedge up the drag 
so that the edges are in line 
with the point b of the pat- 
tern. Fill and ram the drag 
in the usual way. Turn the 
^^*^- ^^- drag over and strike off the 

sand even with the edges. Build a mound with riddled sand 
about the handles, to the part- 




ing line a, Fig. 90, giving as 
gradual a slope as possible. 
Slick the joint well and make 
parting. Place the cope ; set 
the plugs for the sprue and 
riser, and finish in the usual 

manner. Remove the plugs 

and Hft off the cope. (The 

sand will part along the line c-a-b-a-c.) 

place the cope ; clamp and pour. 



'-a. 



::{c^ 



%^Z: li:——^— V^*i^u> 



S. ■■'^■y--(-.yr^-~~~>lu^~-~7T'r>.-'.-'^'^/^\\-ir:'-- 
N ■"«V■^■•'•^v.^.•'■■/*■'►-^'■^• ■•■.■■{---■>;;■:;•.-••• ' • • 



Fig. 90. 

Draw the pattern ; re- 



74 



ELEMENTARY FOUNDRY PRACTICE 




PATTERN WITH REMOVABLE PARTS 

Often some overhanging part makes it impossible to draw 
the ordinary form of pattern from the sand. These parts are 

made detachable, and while 

ramming up, are fastened, 

or skewered, to the pattern 

proper with skewer pins or 

other fastenings which can 

easily be pulled out after the 

pattern has been rammed up, 

Fi^- 91- and thus the withdrawal of 

the pattern proper is possible. The loose pieces can then be 

drawn, leaving a properly formed mold of green sand. 

Loose-piece Pattern. — A loose-piece pattern is one having one 
or more parts held in place by 
pins in such a manner that the 
pieces can be withdrawn, the 
main part of the pattern lifted 
from the mold, and the loose 
pieces then taken out. 

Exercise 27. Loose-piece Pattern. 
Pattern : rectangular block with gibbed ways (Fig. 92). 
Casting : rectangular block with gibbed ways (Fig. 91). 
A pattern made like the casting (Fig. 91) will not draw from 

the sand. So the part shown 
in Fig. 93, which will lift, is 
made, and the overhanging 
part made separately. They 
are held to the main pattern 
with dovetails, as shown in 
Fig. 92. 

Fig. 93- To make the mold : Place 

on the moldboard and make the mold, as in Ex. i. 

To remove the pattern : Lift the part shown in Fig. 93. 




Fig. 92. 




MISCELLANEOUS EXERCISES 



75 



This will leave the mold with the loose pieces a still in the sand 
(Fig. 94). Now slip the pieces a out from under the sand and 
lift them out of the mold. Close the mold ; clamp and pour. 




/o 



//a 



7^< 



vr> air rinilll 



Fig. 94. 

Exercise 28. Removable Boss. 

Pattern : circular pattern with removable boss on one side 
and loose flange on one face (Fig. 95). 

Casting : turbine case. 

To make the mold : Select a three-part flask with cheek the 
height of a, Fig. 95. Lay the pattern on the moldboard with 
the flange side to the board but 
with the flange removed, and with 
the boss hekl in place with a 
skewer pin. Place the cheek in 
position with the cope side to the 
board. Fill and ram the cheek. 
Strike off and make the joint level 
with the drag edge of the cope and 
make parting on sand outside of 
the pattern. Place the drag in 
position ; roughen the sand inside the pattern a little so that it 
will join to the sand in the drag. Fill and ram the drag. Turn 







Fig. 95. 



76 



ELEMENTARY FOUNDRY PRACTICE 



over the cheek and drag. Put on the flange piece of the pat- 
tern. Place the cope in position ; set plugs for sprue and riser^ 
and ram. Remove plug and cut pouring basin. 




IVnWI 



^V>vl ' 



Fig. g6. 



To remove the pattern : Lift off the cope and take out the 
flange part of the pattern and cut the gate. Place a bottom 

board on top of the cheek 

'^^^0.( and Hft the board and cheek. 




j*vj:>>vaYii5M Turn both over and rest on 



Fig. 97. 



the bottom board, as shown in. 

Fig. 97. The green-sand core 
of the center of the pattern will remain on the drag (Fig. 96); 
pull the skewer pin a, Fig. 97, from the boss. Lift out the 




Fig. 98. 



main part of the pattern d, Fig. 97. Draw out the boss pattern 
a, Fig. 98 ; place the core in print d, Fig. 99. Replace cheek 
and cope ; clamp and pour. 

Note. — This casting can be made in a two-part flask, if the pattern is 
made with a print for the boss, as shown in Fig. 100, in which is placed a 
hollow core. 

DRAW-RIM PULLEY 

A pulley having a face of any desired width can be made 
from a single face pattern called "draw-rim pattern." The 



MISCELLANEOUS EXERCISES 



77 



pattern is a ring of the desired diameter, and a height, not 
greater than the narrowest faced pulley desired. The hub and 




f^rwT 



Fig. 99. 



arms are made with a hollow core, or with a regular arm and 
hub pattern. In the latter case a special plate (lifting plate) is 
used to lift the sand inside the rim. 

Exercise 29. Draiv-rivi Pulley with Hollozv Core for Anns. 

Pattern : draw rim. 



Core : hollow core, one sixth of ^y\ \a/ ^ 

e pulley inside the rim. / ^/A \ 



ffl 



the 

Casting : pulley with face width 
as assigned. 

To make the core : Place the drag 
right side up on the bottom board. 
Bed in sand to such a height that 
its distance b6low the top of the 
drag is slightly greater than the 
desired width of face. Riddle in 
sand and bed the ring down to 
such depth that its bottom edge 
is the width of the desired face 
below the top of the drag, as in 
Fig. 1 01. Ram sand nearly to the top of the ring. Direct the 
rammer slightly away from the pattern. Vent well and draw 
up the ring. Take care that it is brought up evenly all around, 




Fig. too. 



78 



ELEMENTARY FOUNDRY PRACTICE 



by placing a straight edge across the edge of the drag and 
measuring down to the ring at several places. Continue filling 

and ramming, and drawing 
the ring, to a point equal in 
distance from the top of the 
drag to one half the width of 
the pulley face plus one half 
the thickness of the arm core. 






iv^Ji 



UJ~^ 



Fig. ioi. 



.•Cv-;:..A;,'/,t.;:-Vi'>". 




Setting the core : Set in the core segments, cutting or bedding 
down for the hub part of the core. Set sprue plug and continue 
the mold by filHng, ramming, and venting as before the core 
was set, until the rim is drawn 
flush with the drag edge. 
Put on parting sand ; set a 
riser over the rim, and ram 
the cope in the usual way, 
venting well. Remove plugs; 
draw pattern ; clamp and 
pour. Figure 102 shows mold 
complete. I'ig. 102. 

Exercise 30. Draiv-rim Pulley {Lifting Ring or Anclio)-). 
Pattern : rim same as in Ex. 27 ; hub and arms. 
Casting : pulley (with face as assigned). 

To make the mold : Proceed as in Ex. 27 and ram and draw 
the rim to a distance equal to half the width of the face called 
for, using all the precautions of venting as before. Bed in the 

arm pattern so that its center is 
exactly in line with the center of 
the pulley face. If the sand does 
not come up to the parting line of 
the arms, add sand, and ram until 
it does. Make parting inside the 
rim. Add riddled sand till the arm 
pattern is covered ; ram lightly ; 
Fig. 103. add enough sand to again cover the 




MISCELLANEOUS EXERCISES 



79 







Fig. 104. 



arm, and place the anchor or lifting plate (Fig. 103) in position 
{a-a, Fig. 104). The anchor, as shown at a in Fig. 103, has 
places tapped for draw spikes. The draw spikes must be left 
in the anchor until the cheek (the part above the anchor inside 
the rim) is rammed. Press into the sand, deeply enough to 
make firm, three small pins to guide the anchor to position after 
removing it from the mold. (These may be short cones or square 
pyramids.) Set a sprue plug on the hub just long enough to 
reach to the top of drag. 
Place a few nails around the 
edges of the anchor, so that 
they wall extend nearly to the 
pattern. Fill and ram both 
inside and outside the ring, as 
before, until the ring has been 
drawn flush with the drag edge, remove the draw spikes, and 
cover the holes with a little heavy paper. Make parting over 
entire surface; place the cope in position; set another sprue 
plug, and ram the cope in the usual way. 

To draw the pattern : Remove sprue plug ; make pouring 
basin and lift off cope. Remove the sprue plug from the cheek 
and cut a gate to connect the two sprues.^ Screw the draw 
spikes into the anchor plate again and lift out the cheek. 
Draw the arm pattern ; replace the cheek ; remove the draw 
spikes ; close the holes with a little sand ; draw the rim pattern ; 
close the mold ; clamp and pour. 

SWEEPING OR STRIKING A CORE 

The expense of making a large core or even a small one when 
only a few castings are wanted can be greatly reduced by 
making a skeleton core box, and striking or sweeping the core 
to the desired shape. Figure 105 shows the plan and elevation 
of a skeleton box and a is the strike. 



1 If one sprue plug is set directly over the other, no gate is necessary. 



8o 



ELEMENTARY FOUNDRY PRACTICE 



Exercise 31. Strike Core. 
Pattern : 90° pipe bend. 
Core : skeleton core. 
Casting : 90° ell or pipe bend. 

To make the core : Mix up an ordinary core mixture and 
fill in the skeleton core box ; press with the hand to approxi- 
mately the desired shape of the 
core, filling the box higher than 
the end pieces. Strike the sand 
off smoothly to the profile of 
the strike used. Remove from 
the box, and bake. Make two 
half cores and paste together as 
in previous exercises. 
To make the mold : Make the mold as in Ex. 4. 
To set the core : Place a chaplet in the mold at the middle, 
and in the middle of the bend, to support the core at its center. 
Place the core in the prints and on the chaplet. Close the 
mold; clamp and pour. 




Fig. 105. 



CHAPTER X 

OPEN MOLDING, SWEEP AND STRIKE WORK 

OPEN MOLDING 

Molds having no cope are called open molds. They must 
be perfectly level to insure uniform thickness of metal. The 
casting must have one flat face. 

Exercise 32. Open Mold. 

Pattern : rectangular block with rectangular hole in center. 

Casting : pouring weight. 

To make mold : Spread out and slightly pack some molding 
sand on the floor. Drive into the floor four stakes, as shown at a, 




Fig. 106. 



Fig. 106, about one foot farther apart than the dimensions of 
the pattern. Nail guideboards b to the posts and level. Make 
both the same height with straightedge c and a level. Fill in 
between the board b with riddled molding sand to about \ inch 



82 ELEMENTARY FOUNDRY PRACTICE 

above their tops. Tamp this sand down level with the guides 
with the face of a board, and strike it off level by drawing the 
straight edge c along the guides. This bed must not be so 
solid as for other molding. It must vent freely or the metal 






:^:^:. 



Fig. 107. 

will boil. Place the pattern on this bed and build up the sand 
around its edges. Strike the sand off level with top of the pat- 
tern with the straight edge, using block under the ends to raise 
it to the proper height. Build a pouring and an overflow basin, 
as shown in Fig. 107, and remove the pattern. 

SWEEP WORK 

In sweep work the mold is made by sweeping out or shaping 
the sand, by revolving a board having the profile of the desired 
mold. Sweep work can be used only for circular forms. It 
is used when only a few castings are desired, and where the 
expense of making the pattern would far outweigh the extra 
expense of making the mold with a sweep. The sweeps are 
boards cut to the desired form, arranged to revolve around a 
stake driven in the floor. 

Exercise 33. Sweep Mold. 

Pattern : two sweeps, one the shape of the outside of the 
casting, and the other the shape of the inside. 

Casting : kettle. 



OPEN MOLDING, SWEEP AND STRIKE WORK 



83 



To sweep the mold : Level off the floor with a little molding 
sand and drive the stake solidly into the floor, leaving enough 
above to operate the sweep. Put sweep a, Fig. 108, on stake. 
Pack the sand about the stake and revolve the sweep until a 
hill is formed the shape of 
the sweep or outside of the 
desired casting. (The sweep 
is made with a beveled edge 
so as to push and pack the 
sand.) Remove the sweep 
and put on parting sand. 
Place the cope in position ; 
set sprue plug, and ram up cope in the usual way, taking care 
not to ram so hard as to spoil the shape of the hill. Remove 
the cope ; put on sweep b and sweep the hill to its shape. 
Remove the sweep and stake; pack sand in the hole left by the 
stake ; close the mold ; weight and pour. 

STRIKE WORK 

Strike Work. — Strike work is similar to sweep work, in that 
it saves the cost of making patterns. But instead of revolving 




Fig. 108. 




/=> after/7 

Fig. 109. 

an arm about a central stake, a straight edge or " strike " is 
drawn horizontally across a guide. The distance a, Fig. 109, is 
equal to the depth to which the sand is to be removed. Ribs or 
grooves can be "struck" on by having projections on or grooves 



84 ELEMENTARY FOUNDRY PRACTICE 

in the " strike." Cores and bosses can also be set at any desired 
place after "striking." 

Exercise 34. Strike Work. 

Pattern: see Fig. 109. 

Casting : curved plate. 

To make the mold : Place the pattern on the moldboard with 
the convex side to the board. Place blocks or wedges under it 
to prevent rocking, and ram up the drag in the usual way. 
Turn over ; make parting, and ram up the cope. (This leaves 
an impression in the cope which matches the top of the desired 
casting.) Remove the cope, and with the " strike " ^brush out 
the sand inside the pattern. Remove the pattern and slick the 
surfaces. Close; clamp and pour. 



CHAPTER XI 

DRY-SAND MOLDING 

Dry-sand molding is similar to green-sand molding, except 
that a core sand mixture is used next to the pattern, and this is 
backed off by molding sand. The mold is then placed in an 
oven and dried. After the mold has been dried, it is given a 
coating of blacking. A dry-sand mold is used when a very 
smooth casting is desired, or where the pressure is great. A 
dry-sand mold should be made in an iron flask to permit its 
being placed in the oven. 

Dry-sand facing, or the mixture used next to the pattern, must 
be open-grained enough to allow the escape of the gases. The 
sand used, therefore, must not contain too much clay. The 
clay will make a strong mold, but will not let the gas escape. A 
facing mixture for ordinary work should be about as follows : 

1 part new molding sand, i part old molding sand. 

2 parts fire sand. Add i part each of flour and sea coal to 
30 parts sand. 

The proportions of fire sand and molding sand must be varied 
somewhat, according to the nature of the sands, so as not to get 
too close a mixture. 

Ramming. — As the dry-sand facing is more open-grained, 
and since the moisture is driven off by drying, a dry-sand mold 
may be rammed much harder than a green-sand mold. As with 
green sand, the mold must be rammed evenly ; otherwise hard 
spots or scabs will be formed on the casting. 

Venting. — Although there is no moisture to pass off in dry- 
sand work the mold must be carefully vented, as the hot metal 
against the facing generates much gas. This gas must be 
carried away to insure a sound casting. In a mold with less 

85 



86 ELEMENTARY FOUNDRY PRACTICE 

than six inches of sand between the casting and the flask, the 
sand must be well filled with ventholes. Above six inches little 
venting is necessary. 

Finishing. — After the pattern has been removed, the mold is 
finished to give it a smooth face from which the casting will 
peel. This is done by dampening the mold face with a spray 
of molasses water and carefully slicking. When the mold has 
been dried, it is given a coating of blacking to close the pores. 

Exercise 35. Diy-saiid Mold. 

Pattern : tie rod sleeve. 

Core : straight core. 

To make the core : Make the core in the usual way. 

To make the mold : Use an iron flask. Use the facing-sand 
mixture given above, or the mixture for large cores on page 51. 
Give the pattern a coating of linseed oil and place on the mold- 
board. Pack around the pattern with the dry-sand facing mix- 
ture, to a depth of about two inches, and finish the drag by 
"backing off " with ordinary molding sand. Vent in the usual 
way. Turn the drag over and make a parting by first brushing 
some oil over the joint, and then putting on the parting sand. 
Place the cope in position. Set in the plugs for the runner and 
riser as in green-sand work. Ram up the cope, using first the 
dry-sand facing mixture and then the molding-sand backing, as 
in the drag. Remove the cope and draw the pattern ; slick the 
face of the mold and dry. When dry, give a coating of black- 
ing. When the glisten of the blacking has disappeared, slick 
the blacking to produce a smooth coating. Do not slick enough 
to bring the moisture back to the surface. 

To set the core : Set the core by resting it in the print de- 
pressions. Be sure the core vents have outlets through the sand 
in the flask. Close the mold; clamp and pour. 



CHAPTER XII 

CUPOLA PRACTICE OR MELTING 

Cupola. — In the foundry, iron is melted in a cupola in direct 
contact with the fuel. The cupola (Fig. no) consists of a cir- 
cular shell a of boiler plate, lined with a fire-brick lining b. 
The shell and Hning rest on a bedplate c. In the bedplate is 
a central circular opening that comes flush with the inside of 
the lining. The cupola is supported on four legs d which 
curve outward so that the doors e can swing between them. 
The hinges of the doors are attached to the bedplate near the 
outside so that when the doors are dropped, they will not inter- 
fere with the free fall of the contents of the cupola. When the 
doors are closed, they are held in position by a gaspipe column, 
placed centrally under them. Well up on one side of the cupola 
is a door / for charging. About three feet below the bottom 
of the door is the charging platform. In front, and at the 
bottom level, is an opening g called the breast opening, in 
which the tap hole for drawing off the metal is found ; a spout 
Ji projects from this breast. A wind box i surrounds the 
cupola near the base, from which air from the blower passes 
into the cupola through circular or rectangular openings / 
called tuyers. The area of these tuyers should be about one-ninth 
of the area of the cupola. An air-tight sliding gate is placed 
opposite each tuyer, arranged with a peephole, so the working of 
the cupola can be observed. Large cupolas have a second row 
of tuyers k about ten inches above the first which are used in 
long heats, as the lower ones become partially closed by slag. 
An opening / is provided in the shell of the cupola directly 
back of the breast opening, but about two inches below the 
bottom of the lower set of tuyers, and fitted with a spout m for 

87 



88 



ELEMENTARY FOUNDRY PRACTICE 




Fig. ho. 



CUPOLA PRACTICE OR MELTING 89 

drawing off the slag. The blast is furnished by either a fan or 
a pressure blower through opening into the wind box. A 
water gauge n is usually attached to the wind box to show the 
pressure of the air. 

LADLES AND CUPOLA TOOLS 

Ladles (Fig. in) are used to catch the molten metal and to 
pour it into the molds. They vary in size from 25-pound 
capacity hand ladles to 20-ton capacity crane ladles. The 
sizes are designated by the weight of the metal they will hold, 
and their names, hand ladles and bull ladles, come from methods 
of handling: them. 




I'lG. III. 

The hand ladles are usually made of pressed steel, the large 
ones being built up of boiler plate or are cast iron. All ladles 
up to |-ton capacity have a lining of cupola daubing mixture, 
varying in thickness with the size and condition of the ladles. 
The lining is plastered on by hand after giving the ladle a 
coating of thick clay wash, and should be, for the sides, from 
I to I inch thick for hand ladles and i to i.^ inches thick for bull 
ladles. The bottom lining should be about one half thicker. The 
very large sizes are lined with fire brick over which a daubing 
mixture is plastered. The linings must be well dried and then 
given a coat of blacking before use. The small ladle Hnings 
can be dried in a core oven, but the large ones have a fire built 



90 ELEMENTARY FOUNDRY PRACTICE 

inside of them. The Hnings are made to last by patching small 
breaks after each time they are used. 

The cupola tools (Fig. 112) are a bott stick, used for forcing 
the bott ball into the tap hole in order to close it ; tapping bar, 
a round bar of |-inch iron with a sharp tapering point of square 



1> 



3 off 6//c/r 



Tap/o/no Bar 



Tz 



T(3/Dp//7f Ch/'Se/ 




Fig. 112. 

section, used for tapping ; tapping chisel, a bar of |-inch round 
iron, made spoon-shape at one end, for trimming the sides of 
the tap hole when it gets clogged ; a skimming rod, to hold 
back the slag when pouring. 

BOTT CLAY 

Mixing. — Mix thoroughly beach or sharp sand, 4 parts with 
I part of flour and about \ part sawdust, and temper a little 
more wet than a core-sand mixture. 

PREPARING AND OPERATING THE CUPOLA 

In preparing a cupola to take off a heat, the following steps 
must be taken in the order given : 

I. Clear away the slag and coke dumped at the close of the 
former heat. All the good coke should be picked out and used 
to fire the core ovens. 



CUPOLA PRACTICE OR MELTING QI 

2. Chip off all of the lumps of slag which have accumulated 
in the lower part of the cupola or melting zone. If the slag has 
formed a thin smooth coating over the lining, it should not be 
chipped* away as it forms the best kind of coating. 

3. Daub up the chipped portion with a daubing mixture 
composed of one-third or one-fourth parts of fire clay and fire sand, 
after wetting with a thick clay wash. The plastering can best be 
done with the hands, and must be rubbed in well, and should slightly 
overhang the tuyers to prevent the slag from entering and 
closing them up. Give the daubed portion a coat of blacking. 

4. Close the bottom doors and support them with gas pipe 
column. 

5. Lay the bottom by covering the doors with a layer of isle 
sand and fine cinders about i inch thick, and tramp it down 
well. Next, place another layer of about the same thickness of 
burned molding sand ; this last layer should be given a slope of 
about I inch to the foot toward the front and center for small 
cupolas and | inch to the foot for large ones. Too much pitch 
will cause too much pressure on the bott, and too little will not 
let the iron run well and cause it to chill at the tap hole. The 
bottom must be tramped evenly all over, and the sides particu- 
larly sohdly. The bottom must be able to vent itself and must 
not be wetter than well-tempered molding sand. It must be 
strong enough to hold the heat, but not so solid that it will not 
break and let the load fall through when the bottom doors are 
dropped. A little daubing mixture should be worked into the 
bottom for a few inches in front and to the sides of the breast 
to strengthen the bottom at this point. On this daubing mixture, 
projecting well into the cupola, lay a piece of i-inch gas pipe, 
and then fill up the hole at the breast with daubing mixture or 
ordinary clay. Withdraw the pipe and recess the hole so that 
the tap hole will be as short as possible, or it will give trouble 
by slagging. 

6. Lay the fire by placing shavings on the bottom, then small 
kindling, next enough large kindling to light the coke, then the 



-Bo/-t j//cA 



92 ELEMENTARY FOUNDRY PRACTICE 

amount of coke determined upon for the bed charge. This bed 
should be level. 

7. Lighting up. From | to i hour before the time to pour, 
light the shavings and let the wood and coke burn under natural 
draft by leaving the peephole slides and tap hole open, and the 
charging door closed. When the wood is burnt out and the 
coke is well on fire, throw in as evenly as possible the bed 
charge of iron. If all is ready to pour, the peephole slides are 
closed, the blower started, and the blast turned on, but not too 
strong at first. The clay bott is made into a ball and shaped, 
as shown in Fig. 113, on the bott stick. Two or three botts 

and bott sticks should al- 
ways be ready when oper- 
ating, for use in case one 
does not stick. The hands 
should be raised rather high 
in forcing the bott home 
so as to give a downward 
pressure on the bott in the tap hole, as shown in Fig. 113. 
The tap hole is left open until about 10 pounds of iron has run 
out. It is then closed until enough iron has accumulated for 
the first pouring. When the bott is broken, the iron is caught 
in a bull ladle suspended on trunnions. After sufficient iron has 
run into the ladle, the tap hole is again hotted up. This opera- 
tion is repeated as long as there is iron to pour. The iron and 
fuel to supply the cupola is charged in alternate layers of coke 
and iron after the blast is started. Should it be desirable to 
delay turning on the blast after the bed is lighted, this can be 
done without injury if the charging door is opened. In any 
case the iron should be charged as soon as the coke is well 
lighted. 

8. Dropping the bottom. When all the iron has been melted 
and drawn off, the bottom must be dropped. This is done by 
pulling out the bottom support. Throw water on the coke to 
quench the fire and deaden the heat. 




CUPOLA PRACTICE OR MELTING 



93 



POURING 
In pouring small castings, the iron can be caught directly in 
the hand ladles. The slag, which floats on top, must be 
skimmed off. The skimming is done by means of a rod, as 
shown at Fig. 114, by placing the blade across the ladle at the 
lip. When filling small ladles from the bull ladle, the 
skimming is done in the bull ladle in a similar manner. 
There is no small degree of skill needed in pouring 
a mold and the work to be done must be known in 
order to judge whether the mold should be 
poured fast or slow. Light, thin work should 
be poured very fast, while heavy work should 
be poured slowly. A steady stream should be 
kept up. The pouring should be into the 





Fig. 114. 

basin away from the runner, which will prevent spilling into 
the mold. The basin, runner, and gate must be kept full. The 
remainder of the metal in the ladle should be poured out as 
soon as a mold is poured cither into a pig or back into the bull 
ladle, for if it is allowed to freeze in the ladle, its removal will 
spoil the lining. 

The more common defects which the pupil will find in castings 
as a result of bad molds, bad or cold iron, are : 

Poured Short. — When the amount of metal in the ladle is not 
enough completely to fill the mold, it is said to be poured short. 

Blowholes. — When the gases are pocketed in the metal 
instead of passing off through the sand, a hole called a blow- 
hole is left in the casting. The cause of this is hard ramming, 
wet sand, and lack of venting. 

Cold Shuts. — When two streams of metal cool so much be- 
fore meeting that they will not fuse together, the casting is said 
to be cold shut. 



94 ELEMENTARY FOUNDRY PRACTICE 

Scabs. — When small patches of the mold face wash or fall 
off, projections like warts are left on the surface of the casting 
which are called scabs. The cause is moisture brought to the 
surface by too much slicking. This moisture, drying out by 
the heat of the metal, allows the skin to flake. 

Sand Holes. — When loose sand or excess facing washes into 
the mold while pouring, it replaces some of the metal and leaves 
a hole called a sand hole. 

Swells. — When the sand is not rammed hard enough, the 
metal will cause the mold to bulge, leaving the casting thicker 
in places than it should be. 

Shrinkage Cracks. — When there is unequal cooling in a 
casting, cracks are sometimes formed called shrinkage cracks. 
When the mold is so firm as to resist the natural shrinkage of 
the casting, it will sometimes cause shrinkage cracks. 

Warping. — When shrinkage strains cause a casting to bend 
or twist, the casting is said to be warped. 

FUEL 

Either hard coal or foundry coke can be used as a cupola 
fuel. Coal will carry a heavier load than coke. It requires a 
stronger blast, melts more slowly, but gives a hotter iron, and 
can be used to better advantage in running off long heats. 
When coke is used, it should be what is known as 72-hour bee- 
hive coke, and as free from ash and sulphur as possible. 

The proportion of fuel to iron, both bed and charges, varies 
greatly, and in a strange cupola must be tried out. Usually, 
however, if the fuel is brought up to 24 inches above the tuyers 
for the bed charge, the amount will be about right, and if the 
iron runs too cold, a little more should be used the next time, 
if too hot, a little less. About 3 pounds of iron to each pound 
of coke makes a good bed charge. The intermediate charges 
of coke should be just sufficient to keep up the bed, or to make 
a layer about 6 inches thick. The iron charge should be from 
8 to 10 pounds for each pound of coke. In using hard coal, 
usually a little less weight can be used. 



CHAPTER XIII 

CLEANING CASTINGS 

As soon as the metal has hardened, the flask should be re- 
moved. The casting should be left in the sand until it is cool. 
To remove the sand from the flask, pick up the mold and drop 
it on the sand heap. This will loosen the sand so that it will 
fall out when the flask is picked up. On snap-flask work, 
remove the slip case. Pile flasks ; slip cases and bottom boards- 
in their proper places. 



I 



T = 



Fig. 115. 

As soon as the castings are cool, lay them in the aisle. 
Break off the sprues and throw them into the scrap pile. Then 
take the castings to the cleaning room. 

Rattler. — Small castings are generally cleaned in a rattler, 
Fig. 115. It consists of a barrel with cast-iron ends and a 
body made of steel channels. There is a small space between 
the channels for the escape of dust. One channel is removable 

95 



96 ELEMENTARY FOUNDRY PRACTICE 

to charge or empty the rattler. The barrel revolves on trun- 
nions, which are attached to the ends. A dust-tight box is 
usually built around the barrel ; the dust is caught in a drawer 
at the bottom. The barrel is revolved by either spur or friction 
gears, and should ran from 30 to 50 revolutions per minute. 
The rattler should be packed quite full of castings ; a few 
sprues and shot iron should also be introduced. It takes about 
half an hour to clean a charge. The cleaning is done by the 
rubbing of the castings and sprues over each other. This 
leaves a clean, smooth surface of gray color. When castings 
of 50 or 100 pounds are cleaned, they must not have thin parts, 
because these parts are likely to break off. 

After the castings have been rattled, the gates and any slight 
projections are ground off on an emery wheel. 

Pickling. — When castings are to be machined, they are 
cleaned by pickling. The castings arc placed on a platform, 
the bottom of which slopes from each side to the center. 
Sulphuric acid diluted with 8 to 10 parts of water is thrown on 
the castings, which are kept wet from 10 to 12 hours. They 
are then washed with hot water. The acid runs from the plat- 
form to a tank and is used over several times. The water 
should be so hot that the castings will dry quickly and not rust. 

The action of the acid is to eat the layer of iron oxide which 
forms on the outside of the castings ; when this is done, clean 
iron is left exposed. Heavy castings are cleaned by pickling 
or by the sand blast. 

Hand Cleaning. — In hand cleaning, the worst of the sand is 
removed by wrapping with a hammer. The casting is then 
rubbed with a wire brush, a piece of an old emery wheel, or 
scraped with an old file. 

Sand Blast. — To clean with a sand blast, the sand is blown 
against the casting with great force. This is a very effective 
means of cleaning. 

The fins and projections are cut off either with a hand or 
pneumatic chisel. 



CHAPTER XIV 

CHILLED AND MALLEABLE CASTINGS 
CHILLED CASTING 

The uses to which many castings are put require that some 
parts be very hard and others soft and tough. Thus, the rim 
and flange of a car wheel must be very hard to stand the wear 
on the rails, while the rest must be tough to resist breaking. 
These conditions are obtained by chilling the surface required 
to be hard. The chilling is effected by placing a chill in the 
mold, at the point which is to be chilled. The other parts of 
the mold are left as in ordinary work. The chill for small work 
is a block of iron of the proper size and shape. For large 
work it is usually made hollow. This permits the passing of 
steam through it to warm it before pouring, and of water for 
cooling after pouring. 

Action. — The carbon in cast iron is in two forms : combined 
and uncombined. When it is combined with the iron, it makes a 
very hard white casting. When it is uncombined, the iron is 
soft and gray. The action of the chill is to cause the iron to 
cool so rapidly that the carbon is held in the combined form. 
The slow cooling of the other parts of the casting allows the 
carbon to change to the uncombined or graphitic form. 

Placing Chill. — The mold is made as in ordinary work, and 
the chill added as a core would be. In some cases the chill 
takes the place of a cheek in three-part work. In order to 
prevent the gathering of moisture on the chill it must be heated 
to about 200° F. before it is placed in the mold. Moisture causes 
blowing and thus prevents the metal from coming in contact 
with the chill. 

H 97 



98 ELEMENTARY FOUNDRY PR.A.CTICE 

Coating Chills. — To prevent the iron from sticking to the 
chill, it must be given a coating after it has been heated. 
Blacking wet with molasses water makes a good coating. 
Shellac and varnish, coated when nearly dry with plumbago, 
are good in some classes of work. Light oil makes a good 
coating when put on in a very thin layer. A heavy layer would 
cause gas, which would hold the metal away from the chill. 

Gates. — The pouring gates must be so arranged that the 
metal will rise on the chill. It must never fall or lie horizon- 
tally on it. The gates must be large and arranged so that the 
metal will quickly cover the chill, and prevent bad spots on the 
surface of the casting. The iron from which a chill is made should 
be of the best grade. It should have very little contraction. 

The thickness of a chill is regulated by the depth to which the 
casting is to be chilled. It must be large enough to carry away 
the heat of the molten metal, and not to rise above the solidifi- 
cation temperatures. 

Depth. — The depth to which the iron is chilled is regulated 
by the rapidity with which the iron is cooled and by its compo- 
sition. The depth to which castings are chilled varies from |- 
to I inch. 

Mixture. — To gain the proper mixture or composition, chem- 
ical analysis is used. (For composition see Appendix.) Before 
pouring a chilled casting, the iron is tested for dejDth of chill ; a 
bar 2 inches square and 6 inches long is cast so that one side 
will be against a chill. This test piece is cooled and broken and, 
the depth of chill observed. If of sufficient depth, the chill mold 
is poured ; if not, the metal is poured into other castings. The 
iron for chilled castings is usually melted in an air or reverbera- 
tory furnace. 

MALLEABLE CAST IRON. 

Malleable Cast Iron. — Cast iron annealed by a thermochemical 
process loses its brittleness and is made tough, producing what 
is called malleable cast iron. It can be bent and hammered con- 
siderably without breaking. Its strength is also greatly increased. 



CHILLED AND MALLEABLF CASTINGS 99 

Process. — The malleableizing proces, by means of heat pro- 
duces a chemical change in the composition of the iron. The 
content of carbon is reduced, and that remaining is changed 
from the combined or hardening form to the graphitic. The 
silica, manganese, and other constituents are also changed. 
This makes the outer part much like wrought iron. 

Iron to be made malleable must have its carbon in the 
combined form. The silica must be low. Phosphorus to 0.15 
per cent is an advantage, but sulphur is detrimental. Manganese 
should be rather high, as it has a beneficial effect and reduces 
the time of the process. 

To make castings malleable, the castings arc packed in iron 
boxes with a substance rich in oxygen. The boxes are sealed and 
placed in a direct-fired furnace, where they are kept at a temper- 
ature of 1800° to 1900° F. for from eight hours to several days, 
the length of time depending on the size of the casting. The 
heat must be uniformly distributed and maintained constant. 
The oven and its contents should be heated slowly, and after the 
process is completed, cooled slowly. Sudden change of tem- 
perature will spoil the castings. It is important that the cast- 
ings should not touch each other in the box. The materials rich 
in oxygen that are generally used are red hematite, mill scale, 
and rusted steel turnings from a machine shop. 

The chemical action which takes place is the uniting of the 
oxygen of the reagents with the carbon, which takes place at high 
temperature. This forms carbon-monoxide gas, which passes off. 

The patterns from which castings that are to be malleableized 
are made should be given particular care in their making. 
Sharp corners should be avoided. Changes from light to 
heavy sections should be gradual, and heavy sections avoided 
whenever possible. 

The hard iron used when malleable castings are to be made 
shrinks greatly and cools rapidly. Therefore the gates must 
be made with the greatest care to prevent the chilling of the 
iron in them. : ■'. 



CHAPTER XV 

BRASS MOLDING 

Difference between Brass and Iron Molding. — Brass molding dif- 
fers but little from iron molding. Usually a finer sand is used, 
and the work, as a rule, is much smaller. The joints are made 
much smoother by the use of fine parting dust and careful 
sHcking. This leaves the casting without fins. The molds are 
rammed about as hard as for iron. 

There are three reasons why molds for brass differ from 
molds for iron : 

1. Brass melts at a much lower temperature. 

2. It is not so fluid as iron. 

3. It has about double the shrinkage of iron. For all of 
these reasons the sand may be much less porous, and yet vent, 
risers being used for the escape of air. On small work a vent 
wire is not used. 

Runners should be larger than for iron, to supply shrinkage. 
The gate should be less shallow. 

The molds should be poured on end so as to give more head, 
and to overcome the sluggishness of the metal. Skimming 
gates should be used. 

Materials. — A very fine natural molding sand is used, because 
most brass work has very fine details. Hence the sand must 
have a larger per cent of alumina to retain the sharp details. 
This is possible as the colder metal requires less venting. 

On fight work, the sand is kept in condition by frequently 
adding new sand. On large work a facing is used as in iron. 

Rattler dust, burned sand, and powdered charcoal are used 
for parting materials, as they are fine and make a clean joint. 

The same tools are used as in iron molding:. 



BRASS MOLDING 



lOI 




Flask. — A special iron flask (Fig. 2) is generally used, the 

pins of which fit very accurately. There are holes in one end : 

one through which the mold 

is poured and one or more 

for risers. Small snap flasks 

may be used, but they must 

register very accurately. 
Clamps. — A clamp (Fig, 

116) is used to hold the 

halves together when the 

mold is standing on end to 

be poured. Fig. 116. 

Spill Trough. — A spill trough, Fig. 117, is used to set the 

mold in while pouring, in 
order to catch any metal 
that may be spilled. A 
layer of sand about an 
^'''- "7- VI jj^^^h thick should be 

spread over the bottom of the trough. 
Drying. — On thin 

work, the surface of the 

mold should be dried 

to prevent the wet sand 

from cooling the metal. 

This is done in two 

ways: (i) with a blow 

torch ; (2) a drying 

stove. 

A drying stove (Fig. 

118) is a sheet-metal 

stove with a projecting 

ledge at the bottom. 

The halves of the 

finished mold are care- 
fully sprayed with mo- Fig. 118. 





I02 



ELEMENTARY FOUNDRY PRACTICE 



lasses water and the flask set on edge on the ledge, with the 
faces next to the stove. When sufficiently dry, the molds are 
closed, clamped, and poured. They should be poured soon 
after the drying or the faces will absorb moisture from the 
rest of the sand in the mold. 

Exercise 36. Ornamental Work {Plaque). 

Pattern : a figure consisting of a thin, flat plate. 

Place pattern face down on the moldboard, a little below the 
center of the flask. Sift on fine sand until the pattern is com- 
pletely covered. Pack the sand about the pattern rather firmly 
with the fingers. Fill the balance of the drag with sand and 
ram as in previous exercises. Turn over and smooth the joint. 
Dust on fine parting dust. Place cope in position ; riddle on 
sand and ram up as in Ex. i, but merely hard enough to stand 
handling. Separate the flask ; spray with molasses water, and 
dust on fine pumice stone from a bag. Place on more parting 
dust. Replace cope, and re-ram to required hardness. Separate 
and draw pattern. Cut the runners, risers, and gates as shown 
in Fig. 1 19. 




Fig. 119. 

The runners should be large and round in section. This 



BILA.SS MOLDING 



103 



insures a heavy head of good, clean metal filling every detail of 
the thin mold before it has time to cool. Skin dry the faces of 
the mold with stove or blow torch. Close, clamp, place on end, 
and pour. If the mold is not skin dried, flour can be dusted 
over the face, allowed to stand for a short time, and then blown 
off. This dries the mold and makes a good 
facing. 

Exercise 37. Core Work for Brass. 

Pattern : candlestick. 

Core : straight-balanced core. 

To make the mold : Put in the sand in a man- 
ner similar to a like pattern for iron, and sur- 
face dry mold. 

To make the core : Proceed as described for 
iron, but mix. in about one third molding sand to 
the regular stock mixture. This will leave a 
smoother surface. 

To set the coT-e : The core is set as a balanced 
core for iron work. 

Cleaning. — Rap the casting to free it from 
sand and drop it into water. This will soften 
the casting, free it from sand, and cause the core 
to blow out. Brass castings are also cleaned by 
placing them in a stone basket and dipping them 
once in a mixture of two parts of commercial 
nitric and one part of sulphuric acid. They arc 
then washed thoroughly and dried in sawdust. 

Melting. — The alloy metals will burn in air when exposed 
to sufficient heat to melt them. To prevent burning, the draft 
is kept down so that no free oxygen will reach the metal. A 
brass furnace should therefore be a natural draft furnace, but 
should be supplied with a blast to make it independent of 
atmospheric conditions. The metal must not come in direct 
contact with the fuel. It is therefore melted in graphite cruci- 
bles. These crucibles are bedded in the fire. Coke is the usual 



Fig. 120. 



I04 



ELEMENTARY FOUNDRY PRACTICE 



fuel. The crucibles are lifted from the fire with tongs (Fig. 
120). 

Brass Furnace. — A section of a brass furnace is shown in 
Fig. 121. 

The top is on, or slightly above, the level of the floor of the 
molding room. On a cast-iron bottom plate a with a circular 
opening rests a shell of boiler plate, lined with firebrick. A top 




Fig. 121. 



plate b, with an opening similar to the bottom, binds the whole 
together. The opening is closed with a cover plate c. At one 
side, about 6 or 8 inches from the top, is an opening d con- 
necting with the smoke flue. The bottom plate rests on steel 
beams and these on a foundation of brick or steel columns. A 
grate e fits in the circular opening in the bottom plate. Ashes 



BRASS MOLDING 



105 



are removed by dumping the grate into the ash pit. The coke 
is charged through the opening in the top plate. 

Operation. — A bed of freshly lighted coke 6 or 8 inches thick 
is laid on the grate. The crucible is placed on this and the coke 
is packed around the crucible, filling the space. The crucible 
should be packed as full of metal as possible, and covered. 
When the metal is melted, the crucible is lifted out and poured. 
Gas Furnace. — Figure 122 shows a gas-fired furnace for melting 
brass or soft metals. It consists of a steel shell a, mounted on 
legs c by trunnions, so that it can be tilted, by turning the wheel 
d, to pour the metal. The shell is lined with a refractory brick 
b, so shaped that a crucible will fit it snugly at several points. 
Thus the crucible is held in place while the furnace is tilted, 
yet space is left for the circulation of the gases. 

The gas and air enter under pressure at e, where they are 
ignited and burned in the combustion chamber /; the burning 
gases circulate about the crucible, and the products of combus- 
tion pass out the top at g. 

These furnaces melt rapidly and are convenient to handle, 
but are noisy. 

Brass and Bronze. — These are 
alloys of copper, and zinc or tin. 
The alloy is usually called brass 
when it is composed of copper 
and zinc, and bronze when com- 
posed of copper and tin. The 
alloys of copper and aluminum, 
copper and manganese, and cop- 
per and phosphorus, are called alu- 
minum bronze, manganese bronze, 
and phosphor bronze. 

To make a brass of a certain 
composition : The required amount ^^^- ^"• 

of copper which has the highest melting point of the metals 
used is first melted. The zinc is then added and thoroughly 




I06 ELEMENTARY FOUNDRY PRACTICE 

stirred until it is melted. Allow the mixture to come to the 
proper temperature. Pull the pot ; skim and pour. 

With bronze, the same method is followed, except that both 
the zinc and tin are stirred in after the pot is drawn. 

In mixing zinc, care must be exercised to plunge the zinc well 
under the surface of the copper, and hold it there with tongs 
until it is melted. 

Some typical compositions of brass and bronze will be found 
in the Appendix. 



GLOSSARY 

Air dried. When a core is left in tlie air so long that it becomes dry before 

baking, it is said to be air dried. 
Alloy. A combination of two or more metals, as copper and tin to form 

bronze. 
Anchor. An appliance to hold the parts of a mold together. 
Bars. See Cleats. 

Bed charge. The first charge of coke and iron used in a cupola. (See Oper- 
ation of Cupola, Chapter XII.) 
Bedding in. Sinking the pattern in the sand to the position in which it is to 

be cast. 
Bellows. See Chapter II, Tools. 
Binders. Materials used in loam, core sand, and facing, to bind the sand 

together. 
Blacking. See Chapter I, Materials. 
Black lead. A form of carbon having a soft, greasy appearance. Also called 

grapJnte. 
Blast. A current of air from a blower or fan into the cupola. 
Blast gage. An instrument for determining the blast pressure in the wind 

box of the cupola. Its usual form is that of a glass tube bent U-shaped. 
Blast pipe. The pipe through which the blast passes to the cupola. 
Blower. A machine which forces air into the cupola. 
Blowholes. Holes in castings, due to air or gas in the metal or mold. 
Bottom board. See Chapter II, Tools.- 
Bott stick. See Chapter XII, Cjtpola Tools. 
Breast. The fire-clay front filling the oj^ening over the spout, in which the 

tap hole is located. 
Bidl ladle. A ladle for carrying molten metal, fitted into a shank with two 

handles. See Fig. III. 
Burnt sand. Sand which has been in contact with molten metal. 
Butting or butt raininmg. Ramming the sand with the flat end of the 

rammer. 
Casting. That which is obtained by pouring molten metal into a mold. 
Chaplet block. A block of wood into which a chaplet stem is driven. 
Chaplct nail. A chaplet resembling a nail, in that it has a flat head on one 

end and a sharp point on the other. 
Chaplets. Iron supports to hold cores in position. See Fig. 80. 
Cheek. The middle part of a flask or mold, when it has more than two parts. 
Cliill. Iron placed in a mold in such a position as to chill a portion of the 

casting, thereby producing a ''chilled casting." 

107 



I08 GLOSSARY 

Chilled casting. A casting, a portion of which is hardened by rapid cooling^ 

induced by contact with a chill. 
Cinder bed. A layer of cinders underneath a pit mold to which the gases are 

led and through which they escape by means of a vent pipe. 
Clay wash. Fire clay mixed with water. See p. 8, Chapter I. 
Coke bed. Used like cinder bed. 
Cold shots. Small particles of metal, formed by the splattering of the metal 

on the damp surface of the mold, which harden rapidly and adhere to the 

casting. 
Cold shuts. When two streams of metal become so cool that they do not 

fuse upon meeting, they form cold shuts. 
Contraction. Shrinking of metal during cooling after casting. 
Cope. The upper part of a flask or mold. 
Core. A body of sand in the mold used to form holes or openings of a 

desired shape in the casting. 
Core barrel. A pipe on which a cylindrical core is formed. 
Core board. A board having the profile of a section of the core. 
Core box. The mold in which the core is formed. 
Core irofis. Bars of iron embedded in a core to strengthen it. 
Core mixture. Seep. 51, Chapter VII. 
Core oven. An oven in which to bake cores. 

Core plate. A piece of heavy sheet iron on which cores are placed for baking. 
Core print. A projection on the pattern which forms an impression in the 

mold into which the core is laid. 
Core sand. Sand free from alumina (clay). 
Core wash. See Blacking. 
Crushing. A crumbling of the mold due to too great a strain in clamping or 

weighting it. 
Cupola. See Chapter XII. 

Cutting over. A turning over of the sand to obtain uniform mixture and temper. 
Dajibing. Plastering over the inside of the cupola with a daubing mixture. 
Daubing mixture. Chapter XII. 
Dowels. Pins used to hold the various parts of the patterns in their relative 

positions. 
Draft. The taper made on the pattern to insure its easy withdrawal from 

the sand. 
Drag. The bottom part of the mold when the latter is in position for pouring. 
Drawing. Removing the pattern from the mold. 

Draw plate. A plate attached to a pattern to facilitate drawing. See Chap- 
ter II, Fig. 20. 
Draw spike. A tool for drawing patterns. Chapter II, Fig. 19. 
Drop out. The falling out of sand from the cope while handling. 
Drying. Evaporation of moisture from the mold. 
Dry sand. A mixture of sand and binder which, after drying, produces a 

strong mold. 



GLOSSARY 109 

Dull iron. Iron too cold for successful pouring. 

Facing. See Chapter I. 

Facing sand. That sand which forms the face of a mold. 

Fan. See Blower. 

Feeder head. See Shrinkage head, Chapter III, p. 31. 

Feeding. Forcing the metal into the mold from the feeder head with a 

feeding rod. 
Feeding rod. A metal rod used in feeding. 
Fiti. A projection on the casting due to an imperfect joint. 
Fire clay. A clay which will stand very great heat. 
Flask. See Chapter II, Figs, i, 2, and 3. 
Flow-off gate. A passage through which the metal overflows from an open 

mold. 
Flux. A material used in the cupola to make the slag more liquid. 
Follow board. A board which conforms to the form of the pattern and forms 

the parting surface. 
Fojcndation plate. A cast iron placed on the bottom of the mold to support 

the sweep stake. 
Founding. The making of metal castings. 
Fusing. The melting of the sand due to the heat of the metal and formation 

of a hard coating which adheres to the casting. 
Gaggers. See Chapter III, p. 23. 

Gangway. A passage between the molding floors leading from the cupola. 
Gate. See Chapter III, p. 27. 
Gatecutter. See Chapter II, Tools. 
Gated pattern. See Chapter IX. 
Gate stick. See Sprue plug. 
Graphite. See Black lead. 

Green sand. Properly tempered molding sand. 
Gutters. Shallow channels at the joint which receive the gases from the vents 

and conduct them to the relief vent. 
Hand ladle. A small vessel for carrying molten metal that is handled by one 

man. 
Hard ranuning. Packing the sand until iiard. 
Hatching up. The roughening of the surfoce of the mold to enable new sand 

better to adhere. 
Hay rope. Hay twisted to form a rope. It is wound around the core barrel 

and covered with loam or core sand to form the core. 
Hot 7netal. Metal in its most fluid state. 
Ladle. An iron vessel lined with fire clay, in which the metal is handled. 

See Bull ladle and Hand ladle.. Fig. 1 1 1 . 
Leveling. Making a level bed of sand. 
Leveling guides. Parallel strips used in leveling. 
Lifter. See Tools., Chapter II. 
Lifting screw. See Chapter II, Tools. 



no GLOSSARY 

Loam. The mixture of sand and clay and venting material used in loam 

molding. 
Loani hoard. See Strike. 

Loam Diold. See Loatn Work in Introduction. 
Loam plate. An iron plate upon which a loam mold is built. 
Loose piece. A portion of the pattern which is removable. 
Melting zone. That portion of the cupola above the tuyers where melting 

takes place. 
Mold. The impression left in the sand by the pattern. 
Mold hoard. Board upon which pattern is placed to make the mold. See 

Chapter II, Tools. 
Molding. The making of the mold. 

Molding machines. A machine by which molding is performed. 
Molding sand. See Introduction. 
Nowel. See Drag. 

Old sand. Used sand that is burned from contact with the metal. 
Parting sand. See Introduction. 
Patching. Repairing broken portions of the mold. 
Pattern. The model from which the mold is formed. 

Peeling. When the casting separates easily from the sand, it is said to peel. 
Pit molding. Making a mold in a pit in the foundry floor. 
J'lnmhago. See Black lead. 
Pouring. Filling the molds with molten metal. 
Pouring hasin. That portion of a gate into which the metal is first poured. 

See Chapter III, p. 27. 
Rammer. See Chapter II, Tools. 
Rapping. Knocking the pattern to loosen it. 
Rapping bar. Bar driven or screwed into a pattern which is struck to loosen 

the pattern. 
Rapping hole. Hole in pattern or rapping plate into which the rapping bar 

is placed. 
Rapping plate. A metal plate attached to a pattern in which the rapping 

hole is located. 
Riddle. See Chapter II, Tools. 
Riser. See Chapter III, p. 27. 
Runner. See Chapter III, p. 27. 

Scabbed castings. Castings having rough or uneven surfaces. 
Scrap. That which has no use as it is. 
Sea coal. Soft coal. 
Shrinkage. Sea Contraction. 

Shrink hole. A depression in the casting due to shrinkage. 
Sinking head. See Feeder head. 
Skim gate. See Chapter III, p. 28. 
Skimmer. A spoon-shaped bar of iron used to hold back slag while pouring 

the mold. 



GLOSSARY HI 

Skinwiing. Holding back the slag with the skimmer. 

Skin drying. Drying the face of the mold. 

Slag. The residue in the cupola from the impurities in the fuel and metal. 

Slag hole. An opening in the cupola through which the slag is removed. 

Slick. See Chapter II, TfwA-. 

Slicking. Finishing the surface of the mold with a slick or trowel. 

Snap flask. See Chapter II, Tools. 

Soldiers. See Chapter 111, p. 24. 

Spongy casting. A casting full of blowholes. 

Spojd. The trough through which the molten metal passes from the tap 

hole to the ladle. 
Spray can. A can from which molasses water is forced in the form of spray 

by blowing through a pipe. 
Sprue. The metal which solidifies in the gate. 
Sprue plug. Plug of wood which forms nmner of gate. 
Stopping of. Filling up an unnecessary portion of a mold. 
Stopping-off piece. Template used in stopping off. a, Fig. 74. 
Straining. Sinking of the sand because of the weight of the metal. 
Strike. A stick used in striking out portions of sand from a mold. 
Stripping plate. The plate which holds the sand in place while the pattern 

is being drawn. 
Strong sand. Molding sand containing much clay. 
Swab. A small quantity of hemp bound together at one end, used to dampen 

the sand around the pattern. 
Swabbing. Dampening the sand around the edge of the pattern. 
Sweep. A board having the profile of the desired mold, which, when revolved 

around a stake, produces that mold. 
Sweep work. Making a mold by means of a sweep. 

Tap hole. Hole in the breast of the cupola through w'lich the metal flows. 

Tapping. Opening the tap hole. 

Tapping bar. Iron bar for tapping. 

Tempering sand. See Cutting over. 

Trowel. See Chapter II, Tools. 

Turning over. Rolling over the parts of the mold. 

Turnover board. See Moldboard. 

Tuyers. Openings through which air is admitted into the cujiola. 

Vent gutter. See Gutters. 

Venting. Making vents. 

Vents. Passages provided for the escape of gases, air. and steam from the mold. 

Vent strings. Strings placed in crooked cores to make vent passages. 

Vent wire. Wire for forming vents. 

Weak sand. Sand containing little clay. 

Wedges. See Chapter II, Tools. 

Wet blacking. See Chapter I. Materials. 

Wind box. See in Chapter Xll, Description of cupola. 



APPENDIX 



MELTING POINT, WEIGHT, TENSILE STRENGTH, AND SPECIFIC 
GRAVITY OF METALS 



Melting Pt. 
Degree F. 



Aluminum 

Aluminum Bronze (io%) 
Antimony 



Brass (common) 
Bronze . 



Bismuth 
Copper . 
Copper wire . 
Glass 



Gun Metal (9 Cu., i tin) 
Iron, Cast 



Iron, Pig 



Iron, Wrought . . 
Lead 

Manganese Bronze . 

Nickel 

Phosphor Bronze 

Platinum . . . . 
Steel, Cast 

Tin 

Zinc 



1300 

1700 

790 

1 500-1900 

1850 

518 
1850 

1 600-2300 

1S50 

2700 



Wt. Wt. 

Cu. Ft. Cu. Inch 
IN Lb. in Lb. 



? 200-3000 



3800 
620 

1800 

2900 
1850 

4500 
2550 

512 

775 



162 

485 
418 

539 

545 
616 

550 
555 
180 

545 

450 



480 
712 

525 
1342 

550 
1342 

490 

459 
424 



0.089 
0.028 
0.244 

0.312 

0-315 

0-355 
0.318 
0.32 
0.180 

0-315 



0.28 

0.410 

0.300 
0.299 
0.320 
0.761 
0.286 

0.264 

0.248 



Tensile Strength 
Lb. per Sq. In. 



fCast 

[ Wire 

jCast 

Wire 

Cast 



j Cast 
[Wire 
1 6,000 

1st melt 

2d melt. 

3d melt. 

Bar 

Wire 

Cast 

Pipe 

Cast 

Rolled 

Cast 

Wire 

Wire 
I Plates 
[Wire 

Cast 

Wire 
j Cast 
[Wire 



23,000 
80,000 

1. 000 
20,000 
49.000 I 
32,000 
65,000 I 

3,200 
22,500 
60,000 

32,000 

90.000 

-23,500 

, 18,000 

. 20.000 

. 52,000 

58.000 

95,000. 

1,800 

2,100 

57,000 

105,000 

38,500 

96,000 

53.000 

60,000 

120,000 

4,600 

7,000 

2,900 



Specific 
Gkavity 



2.6 

7.56 
8.710 

8.3 
8.4 

9-9 
8.6 
8.8 
3-0 
8.4 
6.21 



33 



8.40 


8.10 


8.5. 


21.842 


7.919 


7-3 


6.86 



"3 



114 APPENDIX 

SHRINKAGE OF CASTINGS 

For Loam castings -jL in. per foot. 

Green-sand castings J^ in. per foot. 

Dry-sand castings J^ in. per foot. 

Brass castings ^3_ i^^ pgj. f^Q^^ 

Copper castings ^5_ [^ pgj. f^Q^-^ 

Tin castings | in. per foot. 

Bismuth J>^ in. per foot. 

Zinc rj5g in. per foot. 

Lead ^5_ j^. per foot. 

CUBIC FEET OF EARTH TO A TON 

Sand, river (loaded in wagon) 21 cu. ft. 

Sand, pit (loaded in wagon) 22 cu. ft. 

Gravel, coarse (loaded in wagon) 23 cu. ft. 

Marl (loaded in wagon) 28 cu. ft. 

Clay, stiff (loaded in wagon) 28 cu. ft. 

Chalk, lump (loaded in wagon) 29 cu. ft. 

Earth mold (loaded in wagon) 33 cu. ft. 
One cubic yard of sand weighs about 3000 lb. 

TO TEST THE QUALITY OF IRON 

If fracture gives long silky fibers of leaden gray hue, fibers 
cohering and twisting together before breaking, it may be con- 
sidered a tough, soft iron. A medium, even grain mixed with 
fibers a good sign ; a short, blackish fiber indicating badly re- 
fined iron. A very fine grain denotes a hard, steady iron, apt 
to be cold short, hard to work with a file. Coarse grain, with 
a brilliant crystallized fracture, yellow or brown spots, denotes 
a brittle iron, cold short, working easily when heated, welds 
easily. Cracks on the edge of bars, sign of hot short iron. 
Good iron is readily heated, soft under the hammer, and throws 
out but few sparks. All iron contains more or less carbon, 
the harder the most. The heaviest steel contains the least 
carbon. 



APPENDIX 



115 



PROPORTION OF ALLOYS 

(By wei-ght) 

Bell metal : copper 30 lb., zinc 5-6 lb., tin 10. i lb., lead A-Z- lb. 

Brass, yellow: zinc 10 lb., lead 4 oz., copper 24 lb. 

Bronze metal: antimony i lb., tin 100 lb., copper 2 lb. 

Pewter: tin 4 lb., lead i lb. 

Platinum, mock: copper 4 lb., zinc 18 lb. 

Queen's metal: tin 9 lb., antimony i lb., lead i lb., bismuth 

I lb. 

Rivet metal: tin 5 lb., zinc 2 lb., copper 10 lb. 

Silver (colored metal): tin 50 lb., bismuth i lb., antimony 
3 lb., copper 3 lb. 

Silver (imitation): copper 4 lb., zinc 4 oz. 

Solder, hard: copper i lb., zinc 8 oz. 

Solder, plumbers : tin 2 lb., lead 5 lb. 

Solder, yellow : copper and zinc, equal parts. 

Type metal: lead 9 lb., antimony 2 lb., bismuth 2 lb. 

White metal: copper 5 lb., zinc 3 lb., lead i lb., tin i lb. 



ANALYSIS OF SANDS 1 



Silica . . . • 
Alumina . . ■ 
Iron O.xidc . . 
Calcium Oxide . 
Calcium Carbonate 
Magnesia . • 
Sodium . . • 
Potash . . • 
Combined Water 
Organic Matter 
Specific Gravity 
Degree of fineness 



FIRE 

SAND 



98.04 
1.40 
0.06 
0.02 

16.00 



0.14 



.592 



82.21 
9.48 
4.25 

0.68 
0.32 
0.09 
0.05 
2.64 
0.28 
2.652 
85.00 



MOLDING SAND 



Iron 



Light Medium Heavy 



85.85 

8.37 
2.32 
0.50 
0.29 
0.81 
O.IO 

0.03 



88.40 
6.30 

2.00 

0.78 

0.50 



1.68 


173 


0.15 


0.04 


2.645 


2.630 


66.00 


46.00 



Brass 



Light 



78.86 
7.89 

5-45 
0.50 
1.46 
1. 18 
0.13 
0.09 
3.80 
0.64 
2.640 
95.00 



CORE 
SAND 



85.50 
2.65 
0.85 

2.65 
4.27 
0.04 
0.04 
2.00 
1. 00 



« Analysis by W. G. Scott. 



Il6 APPENDIX 

PROPORTIONS OF VARIOUS ALLOYS IN COMMON USE 

(In lOO parts) 

Babbitt metal: tin 89, copper 3.7, antimony 7.3. 

Fine yellow brass : copper 66, zinc 34. 

Gun metal: copper 90, tin 10. 

White brass: copper 10, zinc 80, tin 10. 

German silver: copper 33.3, zinc 33.4, nickel 33.3. 

Machinery bearing: copper 87.5, tin 12.5. 

Sheathing metal : copper 56, zinc 44. 

FUEL 

I lb. of coal will evaporate from 7 to 10 lb. of water. 
I lb. of dry pine wood will evaporate 4 to 5 lb. of water. 
I ton of anthracite coal requires a space of 42 cu. ft. 
I ton of bituminous coal requires a space of 44 cu. ft. 
I ton of coke requires a space of 80 cu. ft. 
150.35 cu. ft. of air are required for the combustion of i lb. 
of coal. 

RECEIPTS 

Burns : Keep moist with a saturated solution of picric acid. 

Coppering Irons : Melt a layer of cryolite and phosphoric 
acid over the iron, heat to temperature of melted copper, and 
dip in melted copper. 

Hardening Copper : Take 2 lb. of alum, 8 oz. of arsenic, for 
every 40 lb. of copper. Mix alum and arsenic. Melt the copper 
in a crucible and stir in the alum and arsenic mixture. Stir for 
five minutes and pour. (H. D. Chapman, Am. Mac/i.) 

Rust Joint : Wet fine iron borings with sal ammoniac and 
water or hydrochloric acid, and pack into joint. 

Rusting : To prevent iron from, warm it and rub with white 
wax, hold to fire till wax pervades the entire surface. Tools 
can be immersed in linseed oil and the oil allowed to dry on them. 

Silvering Metals Mixture : Dissolve 2 oz. of silver in 3 gr. of 
corrosive sublimate. Add 8 qt. salt, 4 lb. tartaric acid. 

Tinning Acid for Brass and Copper : Muriatic acid i lb., dis- 
solve in acid all the zinc it will take, add 4 oz. sal ammoniac, 
I pt. of water. 



APPENDIX 117 

HINTS CONCERNING THE CUPOLA 1 
When iron runs cold, draw all the melted iron off at once. 

This will prevent the newly melted iron dropping into the dull 

iron in the bottom of the cupola, and being chilled also. 

When slag flows from the tap hole, with a stream of iron, 

when the iron is drawn off close, it is due to too much pitch in 

the sand bottom. 

The formation of slag in a spout is due to use of poor material 

in Hning the spout. 

The cutting away of the spout lining by the stream of molten iron 
is due to the lack of cohesive properties in the lining material. 

When a tap hole closes up with slag and cannot be kept open, 
the slag is generally produced by the melting of the materials 
used in^ making up the front and tap hole. Slag made in the 
cupola flows from the tap hole without clogging it. 

A little sand or clay wash added to the front and spout 
material will generally remedy difficulties. 

Make the spout narrow so the metal will not take ajicw 
channel at each tapping. 

If the sand bottom does not drop readily when the bottom is 
dropped, there is too much clay in the bottom material. Mix a 
little sand and cinder riddled from the dump with it, or some 
well-burnt molding sand. 

A hard-rammed bottom causes iron to boil in the cupola. 

A bottom should not be rammed harder than a mold. 

Wet sand not only causes the metal to boil but hardens it. 
Have the sand no wetter than for a mold. 

Do not use new sand for a bottom. Old sand from the gang- 
way is the best. 

A bad light-up makes a bad heat. The bed must burn evenly 

or it will not melt evenly. 

Never use green wood in lighting up. Use only enough to 

ignite the coke. 
^ Don't burn up the bed before charging the iron. 

A long heat is more economical than a short one, for as a rule 
3 to I is charged on the bed and 10 to i on the charges, and the 
o-reater number of charges melted the less per cent of fuel used. 

1 Trade catalogue, Hill, Griflith and Co. 



ii8 



APPENDIX 



Sparks that fly from the stream of iron as it flows from the 
cupola are oxide of iron and burn very Httle. 

Sparks from a wet tap hole or spout are molten iron and burn 
wherever they strike. 

CHEMICAL COMPOSITION OF PIG IRON FOR VARIOUS KINDS OF 

CASTINGS 

Ordinary machine castings {grey iron) : 

Sulphur not more than 0.05 per cent. 
Phosphorus not more than 0.05 per cent. 
Manganese not more than 0.80 per cent. 
Silicon from 1.75 per cent to 2.75 per cent as specified. 

Malleable cast {white iroii)'. 

Sulphur not more than 0.04 per cent. 
Phosphorus not more than 0.225 per cent. 
Manganese not more than 0.60 per cent. 
Silicon from .75 per cent to 1.50 per cent as specified. 

Chilled iron : 

As for malleable. 

Since the relative proportions of combined and free carbon 
are largely controlled by the silicon, it is not necessary to 
specify except as above. 

THE EFFECT OF COMBINED AND GRAPHITIC CARBON 



Combined Carbon causes 


Graphitic Carbon causes 


Converting CC. into GC. 
causes 


Hardness 


Softness 


Softness 


Brittlene.ss 


Decrease of brittleness 


Decrease of brittleness 


Decrease of tensile 


Decrease of tensile 


Increase of tensile 


strength 


strength 


strength 


Increase of compressiv^e 


Decrease of compressive 


Decrease of compressive 


strength 


strength 


strength 


Decrease of ductility 


Decrease of ductility 


Increase of ductility 


Decrease of tensile 


Decrease of tensile 


Increase of tensile 


resilience 


resilience 


resilience 


Decrease of compressive 


Decrease of compressive 


Decrease of compressive 


resilience 


resilience 


resilience 




Decrease of shrinkage 


Decrease of shrinkage 



INDEX 



Alloys, 105-106. 

Melting points of, 36 n. 

Proportions of, 115, 116. 
Aluminum bronze, 105. 

Anchoring core with chaplets, exercise, 70- 
71- 

Babbitt metal, proportions of alloys in, 116. 

Baking cores, 52-5,5. 

Balanced core, exercise in molding, 59-60. 

Basins, 27. 

Bellows, 14. 

Binders, in dry core molding, 49-50. 

Bismuth, shrinkage of, 114. 

Blacking, 8. 

for cores, 54. 
Black loam, 6. 
Blowholes, 93. 
Bott clay, 90. 
Bott sticks, 90. 
Bottom board, the, 12. 
Brass, proportions of alloys in, 116. 
Brass castings, shrinkage of, 114. 
Brass furnace, 104. 
Brass molding, 100-106. 
Bronze, brass and, 105-106. 
Burns, receipt for, 116. 

Carbon, effect of combined and of graphitic, 

118. 
Castings — 

Chemical composition of pig iron for 
various kinds of, 118. 

Chilled, 97-98. 

Cleaning, 95-96. 

Malleable, 98-99. 

Shrinkage of, 114. 
Chaplets, 64-67. 

Setting, 67. 
Charcoal for facings, 8. 
Charcoal washes, use of, in cores, 50. 
Cinders, use of, in cores, 50. 
Clamps, 17-18. 

in brass molding, loi. 
Clay wash, 8. 

as a base for blacking, 50. 
Coating chills, 98. 
Coke for facings, 8. 
Cold shuts, 93. 



Column base, exercise in molding, 47-48. 

Cope, ramming, 23. 

Copper, receipt for hardening, 116. 

Copper castings, shrinkage of, 114. 

Coppering irons, 116. 

Core binders, 8. 

Cores — 

Composition and making of, 50-51. 

I)r>-, 49-54- 

Molding exercises vvith drj', 55-71. 

Setting, 55 ff., 64 ff. 

Sweeping or striking, 79-80. 

Venting, 55. 
Core sands, 5. 
Corner slicks, 15. 
Crossbars, as holding device, 23. 
Cupola, the, 87-89. 

Hints concerning, 117. 
Cupola practice, S7-94. 
Cupola tools, 89-90. 

Cylinders, exercises in molding, without 
cores, 36-40. 

Drag, ramming the, 22-23. 
Draw plate, the, 16-17. 
Draw-rim pulley, 76-79. 
Draw spikes, 15-16. 
Dry cores, 49-54. 

Molding exercises with, 55-71. 
Drying, methods of, 101-102. 
Dr>'ing stove, 101-102. 
Drj'-sand molding, 85-86. 

Shrinkage of castings, 114. 

Facings, 6-8. 

Blacking, 8. 

Charcoal, 8. 

Coke, 8. 

Dr>'-sand, 85. 

Introduction of new, 20-21. 

Sea coal, 7. 

Talc, 8. 
Facing sand, 6. 

Finishing, in dry-sand molding, 86. 
Finishing cores, 54. 
F'ire clay, use of, in foundries, 8. 
Flasks, 9-11. 

in brass molding, loi. 
Flour, as a binder, 49. 



119 



I20 



INDEX 



Follow board, the, 12. 
Free sands, 5-6. 
Fuel — 

in cupola work, 04. 

Statistics concerning, 116. 
Furnace, in brass molding, 104. 

Gaggers, 23-24. 

Gas furnace, 105. 

Gas pipes, for strengthening cores, 50. 

G;<te cutters, 17. 

Gated patterns in molding, 72-73. 

Gaters, 17. 

Gates and gating, 27-30. 

Gates — 

Pouring, 98. 

Skimming, 30. 
German silver, proportions of alloys in, 116. 
Glue, as a binder, 50. 
Graphite for facings, 7. 
Graphite washes, use of, in cores, 50. 
Green-sand castings, shrinkage of, 114. 
Green-sand cores, molding exercises with, 

44-48. 
Green-sand match, 41-42. 

Hand cleaning of castings, 96. 
Hanging core, molding exercise, 68-70. 
Holding devices, auxiliary, 23-25. 
Hollow core, exercise in molding, 62-63. 

Iron, testing quality of, 114. 
Irregular parting, mold with, 73. 

Ladles, in cupola practice, 89. 
Lead, shrinkage of, 114. 
Lifters, 14. 

Linseed oil, as a binder, 50. 
Loam, for use in foundries, 6. 
Loam castings, shrinkage of, 114. 
Loose-piece patterns, 74. 

Machinery bearing, proportions of alloys in, 

116. 
Malleable castings, chemical composition of 

pig iron for, 118. 
Malleable cast iron, 98-99. 
Manganese bronze, 105. 
Matches, 41-43. 

Green-sand, 41-42. 

Oil, 42. 

Plaster of Paris, 42-43. 
Melting, 87-94. 

in brass molding, 103-104. 
Melting point of metals, 1 13. 
Molasses water as a binder, 50. 
Moldboard, the, 12. 
Molding — 

Brass, 100-106. 



Molding — 

Dry-sand, 85-86. 
Molding exercises — 

with green-sand cores, 44-48. 

without cores, 33-38. 
Molding sands, 2-5. 
Molds — 

Open, 81-82. 

Patching of, 31-32. 

Sweep, 82-83. 

Venting, 25-27. 

Nailed core, exercise in molding, 67. 
Nailing core to bottom board, exercise, 68. 
Nails, as a holding device, 25. 

Oil match, 42. 

Open molds and molding, 81-82. 

Ovens for baking cores, 53-54. 

Parting sand, 5-6. 
Patching, 31-32. 

Pattern cylinder, exercise in molding, 36-38. 
Pattern with removable parts, 74-76. 
Phosphor bronze, 105. 
Pickling, cleaning castings by, 96. 
Pig iron, chemical composition of, for vari- 
ous kinds of castings, 118. 
Pinch bars, 18. 
Placing chill, 97. 

Plaster of Paris, use of, for tilling molds, 36 n. 
Plaster of Paris matches, 42-43. 
Pouring, in cupola practice, 93-94. 
Pouring gates, 98. 
Pulley, draw-rim, 76-79. 

Rammers, 12-13. 
Ramming — 

Cope, 22-23. 

Drag, 22. 

Dry-sand, 85. 
Ramming sand, 21-22. 
Rattler, the, 95-96. 
Rattler dust, 5-6. 
Receipts, 116. 
Rectangular block, exercise in molding, 33- 

36. 
Removable boss, exercise, 75-76. 
Riddle, the, 12. 
Risers, 30. 

Rosin, as a binder, 50. 
Runners, 27. 

Rusting, receipt for, 116. 
Rust joint, receipt for, 116. 

Sand — - 

Holding devices, 23-25. 
Introduction of new, 20-21. 
Preparing the, 19-21. 



INDEX 



121 



Sand — 

Ramming, 21-22. 

Tempering, 21. 
Sand blast, cleaning castings by, q6. 
Sand holes, 94. 
Sands — 

Analysis of, 115. 

Core, s. 

Facing, 6. 

Free, 5-6. 

Grades of, 4-5. 

in brass molding, 100. 

Molding, 2-5. 

Parting, 5-6. 

Production of, 1-2. 

Proportions of, used in core-making, 51. 
Scabs, 94. 
Sea coal facing, 7. 

Segment core, exercise in molding, 61-62. 
Setting bolt hole core and core below the 

surface, exercise, 58-59. 
Setting core below the surface by stopping 

off, exercise, 60-61. 
Setting cores, 55 fl., 64 ff. 
Sheathing metal, proportions of alloys in, 116. 
Shovels, 12. 
Shrinkage cracks, 94. 
Shrinkage heads, 31. 
Shrinkage of castings, 114. 
Silvering metals mixture, ii6. 
Skimming gates, 30. 
Slicks, 13-14. 

Corner, 15. 
Slip cases, 11-12. 
Snap flasks, lo-ii. 
Soft metal, use of, in molding, 36 n. 
Soldiers, 24-25. 
Specific gravity of metals, 113. 



Spill trough, in brass molding, loi. 

Sponges, 15. 

Spraying cans, 52. 

Sprue plug, the, 14-15. 

Sprues, 27-29. 

Stopping off, 32. 

Straightedge, the, 13. 

Strike core, exercise, 80. 

Strike work, 83-84. 

Swabs, 15. 

Sweeping or striking a core, 79-80. 

Sweep work, 82-83. 

Swells, 94. 

Talc for facings, 8. 

Tempering sand, 21. 

Tensile strength of metals, 113. 

Three-part flask, exercises in molding, 46-47. 

Tin castings, shrinkage of, 114. 

Tinning acid for brass and copper, 116. 

Tool boxes, 18. 

Tools, 9-18. 

for core-making, 52. 
Trowels, 13. 
Tuyers, 87. 
Two-part flask, exercise in molding, 45-46. 

Venting a mold, 25-27. 
Venting cores, 55, 85-86. 
Vent rods, 17. 

Warping, 94. 
Wax, use of, in cores, 50. 
Wedge.s, 17-18. 
Weight of metals, 113. 
Weights, 17. 

Zinc, shrinkage of, 114. 



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the dissection of other kinds of machines. 

A knowledge of elementary Practical Mathematics and of the fundamental 
principles of Machine Construction and Drawing has been assumed, and 
it has been taken for granted, since the subjects assist one another very 
greatly, that the student will be studying Applied_ Mechanics at the same 
time that he undertakes the work dealt with in this book. 



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The Practical Telephone Handbook and Guide 
to the Telephonic Exchange 

By JOSEPH POOLE, A.M.I. E.E. London. Fourth edition, 
revised and enlarged 

Cloth, 606 pp., i2mo, $1.75 net 

After the introductory chapter the liook treats of specific subjects such as: — 
Batteries, History, Recei\ers in General Use, Transmitters in Practical 
Use, Sub-station Apparatus, Sub-station Instrument Connections, Inter- 
mediate Switches and Extension Instruments, Intercommunication Tele- 
phones, Switch-board Apparatus, Relay and Lamp Signalling, Small 
Switch-boards, Larger Sub-exchange and Private Branch-exchange 
Switch-boards, Multiple Switch-boards, Magneto Series, Magneto Branch- 
ing, Principles of Common Bafery or Central-energy Working, Common 
Battery Multiple Switch-boards, Junction-line Working, Trunk-lino 
Exchanges, Party-line Working, Apparatus-Room, The Power Plant, 
Traflic Statistics, Aerial Line Construction, Underground Work, Long- 
distance Lines, Pupin System of Line Loading, Submarine Telephone 
Cables, Faults and their Localization, Electrical Measurements, The 
British Insulated Co.'s Telephone System and later Post Oflice Exchange 
Practice, Special Exchange Systems, .Automatic Exchanges, Development 
Studies or Fundamental Plans, Wireless Telephony, and Miscellaneous 
Applications. 

A Treatise on Hydraulics 

By WILLLAM CAWTHORNE UNWIN, LL.D., F.R.S. 
London, 1907 

Cloth, 327 pp., Svo, $4.23 nd 

Professor Unwin has brought together here information concerning an 
accumulation of experimental data relative to hydraulic problems which 
will be of immense service to engineers in deciding questions. He has 
avoided one of the great diflicuhies which has arisen heretofore in treating 
hydraulics by giving so sufficient an account of experimental investigations 
as to enable the student to realize the limitations of formula; and the 
degree of confidence which can be placed in calculations. Strong features 
of the book are the full references to the primary sources of information, 
the treatment of the problems dealing with compressible fluid, and the 
selection of numerical problems. 

The Mechanics of Pumping Machinery 

A Text-book for Technical Schools and a Guide for Practical 
Engineers. By Dr. JULIUS WEISBACH and Professor 
GUSTAV HERRMANN. London 

Cloth, 300 pp., Svo, $4.00 nd 

The standard discussion of water-raising machinery, with references to 
special reading on mining pumps and city waterworks. 



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Iron and Steel Manufacture 

A Text-book for Beginners. By ARTHUR H. HIORNS. 
London. Fourth edition, completely revised and enlarged, 
1907 

Cloth, 211 pp., i2tflo, $1.00 net 

Presents the fundamental principles of the various processes employed in 
the manufacture of iron and steel in an elementary manner. Valuable in 
preparing the beginner for more advanced study. 

Mixed Metals, or Metallic Alloys 

By ARTHUR F. HIORNS. Second edition, completely 
revised and enlarged. London, 1901 

Cloth, 445 pp., i2mo, $1.50 net 

It aims to supply the needs of students and others desiring a more intimate 
acquaintance with the nature and properties of metals in the alloyed state 
as well as in the free state. It deals with metals in a state of admi.xture 
and shows how such mixtures are useful!}' employed. 



Steel and Iron 

For Advanced Students. By ARTHUR H. HIORNS. Lon- 
don, 1903 

Cloth, 514 pp., i2mo, $2.50 net 

A text-book dealing with the more scientific aspects of the iron and steel 
industries. While the book deals mainly with general principles, an 
endeavor has been made to make these as comprehensive as possible. 
The sub-title " for advanced students " is not intended to convey the 
idea that the book is of a highly advanced character, but that it is de- 
signed for students pursuing a second or third year's course in a college or 
technical school. 



A Text-book of Elementary Metallurgy 

For the Use of Students. By ARTHUR E. HIORNS. Lon- . 
don. Second edition, completely revised, 1895 ; reprinted, 
1906 

Cloth, 212 pp., i2mo, $0.80 net 

An elementary treatise on Metallurgy adapted to the capacity of a be- 
ginner, and dealing rather with principles than with detailed processes. 



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